WIP relocation test

Reorder checks so it checks whether the timeline exists
before writing something to disk, possibly replacing valid content

.circleci/ansible/neon-stress.hosts

@@ -12,6 +12,7 @@ pageservers
 safekeepers
 
 [storage:vars]
+env_name = neon-stress
 console_mgmt_base_url = http://neon-stress-console.local
 bucket_name           = neon-storage-ireland
 bucket_region         = eu-west-1

libs/remote_storage/src/lib.rs

@@ -12,8 +12,10 @@ use std::{
     borrow::Cow,
     collections::HashMap,
     ffi::OsStr,
+    fmt::Debug,
     num::{NonZeroU32, NonZeroUsize},
     path::{Path, PathBuf},
+    pin::Pin,
 };
 
 use anyhow::{bail, Context};
@@ -70,11 +72,7 @@ pub trait RemoteStorage: Send + Sync {
 
     /// Streams the remote storage entry contents into the buffered writer given, returns the filled writer.
     /// Returns the metadata, if any was stored with the file previously.
-    async fn download(
-        &self,
-        from: &Self::RemoteObjectId,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>>;
+    async fn download(&self, from: &Self::RemoteObjectId) -> Result<Download, DownloadError>;
 
     /// Streams a given byte range of the remote storage entry contents into the buffered writer given, returns the filled writer.
     /// Returns the metadata, if any was stored with the file previously.
@@ -83,12 +81,49 @@ pub trait RemoteStorage: Send + Sync {
         from: &Self::RemoteObjectId,
         start_inclusive: u64,
         end_exclusive: Option<u64>,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>>;
+    ) -> Result<Download, DownloadError>;
 
     async fn delete(&self, path: &Self::RemoteObjectId) -> anyhow::Result<()>;
 }
 
+pub struct Download {
+    pub download_stream: Pin<Box<dyn io::AsyncRead + Unpin + Send>>,
+    /// Extra key-value data, associated with the current remote file.
+    pub metadata: Option<StorageMetadata>,
+}
+
+impl Debug for Download {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Download")
+            .field("metadata", &self.metadata)
+            .finish()
+    }
+}
+
+#[derive(Debug)]
+pub enum DownloadError {
+    /// Validation or other error happened due to user input.
+    BadInput(anyhow::Error),
+    /// The file was not found in the remote storage.
+    NotFound,
+    /// The file was found in the remote storage, but the download failed.
+    Other(anyhow::Error),
+}
+
+impl std::fmt::Display for DownloadError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            DownloadError::BadInput(e) => {
+                write!(f, "Failed to download a remote file due to user input: {e}")
+            }
+            DownloadError::NotFound => write!(f, "No file found for the remote object id given"),
+            DownloadError::Other(e) => write!(f, "Failed to download a remote file: {e}"),
+        }
+    }
+}
+
+impl std::error::Error for DownloadError {}
+
 /// Every storage, currently supported.
 /// Serves as a simple way to pass around the [`RemoteStorage`] without dealing with generics.
 pub enum GenericRemoteStorage {
@@ -180,7 +215,7 @@ pub struct S3Config {
     pub concurrency_limit: NonZeroUsize,
 }
 
-impl std::fmt::Debug for S3Config {
+impl Debug for S3Config {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("S3Config")
             .field("bucket_name", &self.bucket_name)

libs/remote_storage/src/local_fs.rs

@@ -17,7 +17,7 @@ use tokio::{
 };
 use tracing::*;
 
-use crate::path_with_suffix_extension;
+use crate::{path_with_suffix_extension, Download, DownloadError};
 
 use super::{strip_path_prefix, RemoteStorage, StorageMetadata};
 
@@ -192,15 +192,12 @@ impl RemoteStorage for LocalFs {
         Ok(())
     }
 
-    async fn download(
-        &self,
-        from: &Self::RemoteObjectId,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>> {
-        let file_path = self.resolve_in_storage(from)?;
-
-        if file_path.exists() && file_path.is_file() {
-            let mut source = io::BufReader::new(
+    async fn download(&self, from: &Self::RemoteObjectId) -> Result<Download, DownloadError> {
+        let file_path = self
+            .resolve_in_storage(from)
+            .map_err(DownloadError::BadInput)?;
+        if file_exists(&file_path).map_err(DownloadError::BadInput)? {
+            let source = io::BufReader::new(
                 fs::OpenOptions::new()
                     .read(true)
                     .open(&file_path)
@@ -210,22 +207,20 @@ impl RemoteStorage for LocalFs {
                             "Failed to open source file '{}' to use in the download",
                             file_path.display()
                         )
-                    })?,
+                    })
+                    .map_err(DownloadError::Other)?,
             );
-            io::copy(&mut source, to).await.with_context(|| {
-                format!(
-                    "Failed to download file '{}' from the local storage",
-                    file_path.display()
-                )
-            })?;
-            source.flush().await?;
 
-            self.read_storage_metadata(&file_path).await
+            let metadata = self
+                .read_storage_metadata(&file_path)
+                .await
+                .map_err(DownloadError::Other)?;
+            Ok(Download {
+                metadata,
+                download_stream: Box::pin(source),
+            })
         } else {
-            bail!(
-                "File '{}' either does not exist or is not a file",
-                file_path.display()
-            )
+            Err(DownloadError::NotFound)
         }
     }
 
@@ -234,22 +229,19 @@ impl RemoteStorage for LocalFs {
         from: &Self::RemoteObjectId,
         start_inclusive: u64,
         end_exclusive: Option<u64>,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>> {
+    ) -> Result<Download, DownloadError> {
         if let Some(end_exclusive) = end_exclusive {
-            ensure!(
-                end_exclusive > start_inclusive,
-                "Invalid range, start ({}) is bigger then end ({:?})",
-                start_inclusive,
-                end_exclusive
-            );
+            if end_exclusive <= start_inclusive {
+                return Err(DownloadError::Other(anyhow::anyhow!("Invalid range, start ({start_inclusive}) is not less than end_exclusive ({end_exclusive:?})")));
+            };
             if start_inclusive == end_exclusive.saturating_sub(1) {
-                return Ok(None);
+                return Err(DownloadError::Other(anyhow::anyhow!("Invalid range, start ({start_inclusive}) and end_exclusive ({end_exclusive:?}) difference is zero bytes")));
             }
         }
-        let file_path = self.resolve_in_storage(from)?;
-
-        if file_path.exists() && file_path.is_file() {
+        let file_path = self
+            .resolve_in_storage(from)
+            .map_err(DownloadError::BadInput)?;
+        if file_exists(&file_path).map_err(DownloadError::BadInput)? {
             let mut source = io::BufReader::new(
                 fs::OpenOptions::new()
                     .read(true)
@@ -260,31 +252,31 @@ impl RemoteStorage for LocalFs {
                             "Failed to open source file '{}' to use in the download",
                             file_path.display()
                         )
-                    })?,
+                    })
+                    .map_err(DownloadError::Other)?,
             );
             source
                 .seek(io::SeekFrom::Start(start_inclusive))
                 .await
-                .context("Failed to seek to the range start in a local storage file")?;
-            match end_exclusive {
-                Some(end_exclusive) => {
-                    io::copy(&mut source.take(end_exclusive - start_inclusive), to).await
-                }
-                None => io::copy(&mut source, to).await,
-            }
-            .with_context(|| {
-                format!(
-                    "Failed to download file '{}' range from the local storage",
-                    file_path.display()
-                )
-            })?;
+                .context("Failed to seek to the range start in a local storage file")
+                .map_err(DownloadError::Other)?;
+            let metadata = self
+                .read_storage_metadata(&file_path)
+                .await
+                .map_err(DownloadError::Other)?;
 
-            self.read_storage_metadata(&file_path).await
+            Ok(match end_exclusive {
+                Some(end_exclusive) => Download {
+                    metadata,
+                    download_stream: Box::pin(source.take(end_exclusive - start_inclusive)),
+                },
+                None => Download {
+                    metadata,
+                    download_stream: Box::pin(source),
+                },
+            })
         } else {
-            bail!(
-                "File '{}' either does not exist or is not a file",
-                file_path.display()
-            )
+            Err(DownloadError::NotFound)
         }
     }
 
@@ -352,6 +344,19 @@ async fn create_target_directory(target_file_path: &Path) -> anyhow::Result<()>
     Ok(())
 }
 
+fn file_exists(file_path: &Path) -> anyhow::Result<bool> {
+    if file_path.exists() {
+        ensure!(
+            file_path.is_file(),
+            "file path '{}' is not a file",
+            file_path.display()
+        );
+        Ok(true)
+    } else {
+        Ok(false)
+    }
+}
+
 #[cfg(test)]
 mod pure_tests {
     use tempfile::tempdir;
@@ -518,6 +523,31 @@ mod fs_tests {
     use std::{collections::HashMap, io::Write};
     use tempfile::tempdir;
 
+    async fn read_and_assert_remote_file_contents(
+        storage: &LocalFs,
+        #[allow(clippy::ptr_arg)]
+        // have to use &PathBuf due to `storage.local_path` parameter requirements
+        remote_storage_path: &PathBuf,
+        expected_metadata: Option<&StorageMetadata>,
+    ) -> anyhow::Result<String> {
+        let mut download = storage
+            .download(remote_storage_path)
+            .await
+            .map_err(|e| anyhow::anyhow!("Download failed: {e}"))?;
+        ensure!(
+            download.metadata.as_ref() == expected_metadata,
+            "Unexpected metadata returned for the downloaded file"
+        );
+
+        let mut contents = String::new();
+        download
+            .download_stream
+            .read_to_string(&mut contents)
+            .await
+            .context("Failed to read remote file contents into string")?;
+        Ok(contents)
+    }
+
     #[tokio::test]
     async fn upload_file() -> anyhow::Result<()> {
         let workdir = tempdir()?.path().to_owned();
@@ -568,15 +598,7 @@ mod fs_tests {
         let upload_name = "upload_1";
         let upload_target = upload_dummy_file(&workdir, &storage, upload_name, None).await?;
 
-        let mut content_bytes = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let metadata = storage.download(&upload_target, &mut content_bytes).await?;
-        assert!(
-            metadata.is_none(),
-            "No metadata should be returned for no metadata upload"
-        );
-
-        content_bytes.flush().await?;
-        let contents = String::from_utf8(content_bytes.into_inner().into_inner())?;
+        let contents = read_and_assert_remote_file_contents(&storage, &upload_target, None).await?;
         assert_eq!(
             dummy_contents(upload_name),
             contents,
@@ -584,13 +606,9 @@ mod fs_tests {
         );
 
         let non_existing_path = PathBuf::from("somewhere").join("else");
-        match storage.download(&non_existing_path, &mut io::sink()).await {
-            Ok(_) => panic!("Should not allow downloading non-existing storage files"),
-            Err(e) => {
-                let error_string = e.to_string();
-                assert!(error_string.contains("does not exist"));
-                assert!(error_string.contains(&non_existing_path.display().to_string()));
-            }
+        match storage.download(&non_existing_path).await {
+            Err(DownloadError::NotFound) => {} // Should get NotFound for non existing keys
+            other => panic!("Should get a NotFound error when downloading non-existing storage files, but got: {other:?}"),
         }
         Ok(())
     }
@@ -603,58 +621,31 @@ mod fs_tests {
         let upload_name = "upload_1";
         let upload_target = upload_dummy_file(&workdir, &storage, upload_name, None).await?;
 
-        let mut full_range_bytes = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let metadata = storage
-            .download_byte_range(&upload_target, 0, None, &mut full_range_bytes)
-            .await?;
-        assert!(
-            metadata.is_none(),
-            "No metadata should be returned for no metadata upload"
-        );
-        full_range_bytes.flush().await?;
+        let full_range_download_contents =
+            read_and_assert_remote_file_contents(&storage, &upload_target, None).await?;
         assert_eq!(
             dummy_contents(upload_name),
-            String::from_utf8(full_range_bytes.into_inner().into_inner())?,
+            full_range_download_contents,
             "Download full range should return the whole upload"
         );
 
-        let mut zero_range_bytes = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let same_byte = 1_000_000_000;
-        let metadata = storage
-            .download_byte_range(
-                &upload_target,
-                same_byte,
-                Some(same_byte + 1), // exclusive end
-                &mut zero_range_bytes,
-            )
-            .await?;
-        assert!(
-            metadata.is_none(),
-            "No metadata should be returned for no metadata upload"
-        );
-        zero_range_bytes.flush().await?;
-        assert!(
-            zero_range_bytes.into_inner().into_inner().is_empty(),
-            "Zero byte range should not download any part of the file"
-        );
-
         let uploaded_bytes = dummy_contents(upload_name).into_bytes();
         let (first_part_local, second_part_local) = uploaded_bytes.split_at(3);
 
-        let mut first_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let metadata = storage
-            .download_byte_range(
-                &upload_target,
-                0,
-                Some(first_part_local.len() as u64),
-                &mut first_part_remote,
-            )
+        let mut first_part_download = storage
+            .download_byte_range(&upload_target, 0, Some(first_part_local.len() as u64))
             .await?;
         assert!(
-            metadata.is_none(),
+            first_part_download.metadata.is_none(),
             "No metadata should be returned for no metadata upload"
         );
 
+        let mut first_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
+        io::copy(
+            &mut first_part_download.download_stream,
+            &mut first_part_remote,
+        )
+        .await?;
         first_part_remote.flush().await?;
         let first_part_remote = first_part_remote.into_inner().into_inner();
         assert_eq!(
@@ -663,20 +654,24 @@ mod fs_tests {
             "First part bytes should be returned when requested"
         );
 
-        let mut second_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let metadata = storage
+        let mut second_part_download = storage
             .download_byte_range(
                 &upload_target,
                 first_part_local.len() as u64,
                 Some((first_part_local.len() + second_part_local.len()) as u64),
-                &mut second_part_remote,
             )
             .await?;
         assert!(
-            metadata.is_none(),
+            second_part_download.metadata.is_none(),
             "No metadata should be returned for no metadata upload"
         );
 
+        let mut second_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
+        io::copy(
+            &mut second_part_download.download_stream,
+            &mut second_part_remote,
+        )
+        .await?;
         second_part_remote.flush().await?;
         let second_part_remote = second_part_remote.into_inner().into_inner();
         assert_eq!(
@@ -696,11 +691,30 @@ mod fs_tests {
         let upload_name = "upload_1";
         let upload_target = upload_dummy_file(&workdir, &storage, upload_name, None).await?;
 
+        let start = 1_000_000_000;
+        let end = start + 1;
+        match storage
+            .download_byte_range(
+                &upload_target,
+                start,
+                Some(end), // exclusive end
+            )
+            .await
+        {
+            Ok(_) => panic!("Should not allow downloading wrong ranges"),
+            Err(e) => {
+                let error_string = e.to_string();
+                assert!(error_string.contains("zero bytes"));
+                assert!(error_string.contains(&start.to_string()));
+                assert!(error_string.contains(&end.to_string()));
+            }
+        }
+
         let start = 10000;
         let end = 234;
         assert!(start > end, "Should test an incorrect range");
         match storage
-            .download_byte_range(&upload_target, start, Some(end), &mut io::sink())
+            .download_byte_range(&upload_target, start, Some(end))
             .await
         {
             Ok(_) => panic!("Should not allow downloading wrong ranges"),
@@ -712,18 +726,6 @@ mod fs_tests {
             }
         }
 
-        let non_existing_path = PathBuf::from("somewhere").join("else");
-        match storage
-            .download_byte_range(&non_existing_path, 1, Some(3), &mut io::sink())
-            .await
-        {
-            Ok(_) => panic!("Should not allow downloading non-existing storage file ranges"),
-            Err(e) => {
-                let error_string = e.to_string();
-                assert!(error_string.contains("does not exist"));
-                assert!(error_string.contains(&non_existing_path.display().to_string()));
-            }
-        }
         Ok(())
     }
 
@@ -762,35 +764,26 @@ mod fs_tests {
         let upload_target =
             upload_dummy_file(&workdir, &storage, upload_name, Some(metadata.clone())).await?;
 
-        let mut content_bytes = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let full_download_metadata = storage.download(&upload_target, &mut content_bytes).await?;
-
-        content_bytes.flush().await?;
-        let contents = String::from_utf8(content_bytes.into_inner().into_inner())?;
+        let full_range_download_contents =
+            read_and_assert_remote_file_contents(&storage, &upload_target, Some(&metadata)).await?;
         assert_eq!(
             dummy_contents(upload_name),
-            contents,
+            full_range_download_contents,
             "We should upload and download the same contents"
         );
 
-        assert_eq!(
-            full_download_metadata.as_ref(),
-            Some(&metadata),
-            "We should get the same metadata back for full download"
-        );
-
         let uploaded_bytes = dummy_contents(upload_name).into_bytes();
         let (first_part_local, _) = uploaded_bytes.split_at(3);
 
-        let mut first_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
-        let partial_download_metadata = storage
-            .download_byte_range(
-                &upload_target,
-                0,
-                Some(first_part_local.len() as u64),
-                &mut first_part_remote,
-            )
+        let mut partial_download_with_metadata = storage
+            .download_byte_range(&upload_target, 0, Some(first_part_local.len() as u64))
             .await?;
+        let mut first_part_remote = io::BufWriter::new(std::io::Cursor::new(Vec::new()));
+        io::copy(
+            &mut partial_download_with_metadata.download_stream,
+            &mut first_part_remote,
+        )
+        .await?;
         first_part_remote.flush().await?;
         let first_part_remote = first_part_remote.into_inner().into_inner();
         assert_eq!(
@@ -800,8 +793,8 @@ mod fs_tests {
         );
 
         assert_eq!(
-            partial_download_metadata.as_ref(),
-            Some(&metadata),
+            partial_download_with_metadata.metadata,
+            Some(metadata),
             "We should get the same metadata back for partial download"
         );
 
@@ -843,7 +836,7 @@ mod fs_tests {
     }
 
     fn dummy_contents(name: &str) -> String {
-        format!("contents for {}", name)
+        format!("contents for {name}")
     }
 
     async fn list_files_sorted(storage: &LocalFs) -> anyhow::Result<Vec<PathBuf>> {

libs/remote_storage/src/s3_bucket.rs

@@ -9,17 +9,17 @@ use std::path::{Path, PathBuf};
 use anyhow::Context;
 use rusoto_core::{
     credential::{InstanceMetadataProvider, StaticProvider},
-    HttpClient, Region,
+    HttpClient, Region, RusotoError,
 };
 use rusoto_s3::{
-    DeleteObjectRequest, GetObjectRequest, ListObjectsV2Request, PutObjectRequest, S3Client,
-    StreamingBody, S3,
+    DeleteObjectRequest, GetObjectError, GetObjectRequest, ListObjectsV2Request, PutObjectRequest,
+    S3Client, StreamingBody, S3,
 };
 use tokio::{io, sync::Semaphore};
 use tokio_util::io::ReaderStream;
 use tracing::debug;
 
-use crate::{strip_path_prefix, RemoteStorage, S3Config};
+use crate::{strip_path_prefix, Download, DownloadError, RemoteStorage, S3Config};
 
 use super::StorageMetadata;
 
@@ -187,6 +187,39 @@ impl S3Bucket {
             concurrency_limiter: Semaphore::new(aws_config.concurrency_limit.get()),
         })
     }
+
+    async fn download_object(&self, request: GetObjectRequest) -> Result<Download, DownloadError> {
+        let _guard = self
+            .concurrency_limiter
+            .acquire()
+            .await
+            .context("Concurrency limiter semaphore got closed during S3 download")
+            .map_err(DownloadError::Other)?;
+
+        metrics::inc_get_object();
+
+        match self.client.get_object(request).await {
+            Ok(object_output) => match object_output.body {
+                None => {
+                    metrics::inc_get_object_fail();
+                    Err(DownloadError::Other(anyhow::anyhow!(
+                        "Got no body for the S3 object given"
+                    )))
+                }
+                Some(body) => Ok(Download {
+                    metadata: object_output.metadata.map(StorageMetadata),
+                    download_stream: Box::pin(io::BufReader::new(body.into_async_read())),
+                }),
+            },
+            Err(RusotoError::Service(GetObjectError::NoSuchKey(_))) => Err(DownloadError::NotFound),
+            Err(e) => {
+                metrics::inc_get_object_fail();
+                Err(DownloadError::Other(anyhow::anyhow!(
+                    "Failed to download S3 object: {e}"
+                )))
+            }
+        }
+    }
 }
 
 #[async_trait::async_trait]
@@ -283,38 +316,13 @@ impl RemoteStorage for S3Bucket {
         Ok(())
     }
 
-    async fn download(
-        &self,
-        from: &Self::RemoteObjectId,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>> {
-        let _guard = self
-            .concurrency_limiter
-            .acquire()
-            .await
-            .context("Concurrency limiter semaphore got closed during S3 download")?;
-
-        metrics::inc_get_object();
-
-        let object_output = self
-            .client
-            .get_object(GetObjectRequest {
-                bucket: self.bucket_name.clone(),
-                key: from.key().to_owned(),
-                ..GetObjectRequest::default()
-            })
-            .await
-            .map_err(|e| {
-                metrics::inc_get_object_fail();
-                e
-            })?;
-
-        if let Some(body) = object_output.body {
-            let mut from = io::BufReader::new(body.into_async_read());
-            io::copy(&mut from, to).await?;
-        }
-
-        Ok(object_output.metadata.map(StorageMetadata))
+    async fn download(&self, from: &Self::RemoteObjectId) -> Result<Download, DownloadError> {
+        self.download_object(GetObjectRequest {
+            bucket: self.bucket_name.clone(),
+            key: from.key().to_owned(),
+            ..GetObjectRequest::default()
+        })
+        .await
     }
 
     async fn download_byte_range(
@@ -322,8 +330,7 @@ impl RemoteStorage for S3Bucket {
         from: &Self::RemoteObjectId,
         start_inclusive: u64,
         end_exclusive: Option<u64>,
-        to: &mut (impl io::AsyncWrite + Unpin + Send + Sync),
-    ) -> anyhow::Result<Option<StorageMetadata>> {
+    ) -> Result<Download, DownloadError> {
         // S3 accepts ranges as https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
         // and needs both ends to be exclusive
         let end_inclusive = end_exclusive.map(|end| end.saturating_sub(1));
@@ -331,34 +338,14 @@ impl RemoteStorage for S3Bucket {
             Some(end_inclusive) => format!("bytes={}-{}", start_inclusive, end_inclusive),
             None => format!("bytes={}-", start_inclusive),
         });
-        let _guard = self
-            .concurrency_limiter
-            .acquire()
-            .await
-            .context("Concurrency limiter semaphore got closed during S3 range download")?;
 
-        metrics::inc_get_object();
-
-        let object_output = self
-            .client
-            .get_object(GetObjectRequest {
-                bucket: self.bucket_name.clone(),
-                key: from.key().to_owned(),
-                range,
-                ..GetObjectRequest::default()
-            })
-            .await
-            .map_err(|e| {
-                metrics::inc_get_object_fail();
-                e
-            })?;
-
-        if let Some(body) = object_output.body {
-            let mut from = io::BufReader::new(body.into_async_read());
-            io::copy(&mut from, to).await?;
-        }
-
-        Ok(object_output.metadata.map(StorageMetadata))
+        self.download_object(GetObjectRequest {
+            bucket: self.bucket_name.clone(),
+            key: from.key().to_owned(),
+            range,
+            ..GetObjectRequest::default()
+        })
+        .await
     }
 
     async fn delete(&self, path: &Self::RemoteObjectId) -> anyhow::Result<()> {

pageserver/src/layered_repository.rs

@@ -232,23 +232,32 @@ impl Repository for LayeredRepository {
 
     fn create_empty_timeline(
         &self,
-        timelineid: ZTimelineId,
+        timeline_id: ZTimelineId,
         initdb_lsn: Lsn,
     ) -> Result<Arc<LayeredTimeline>> {
         let mut timelines = self.timelines.lock().unwrap();
+        let vacant_timeline_entry = match timelines.entry(timeline_id) {
+            Entry::Occupied(_) => bail!("Timeline already exists"),
+            Entry::Vacant(vacant_entry) => vacant_entry,
+        };
+
+        let timeline_path = self.conf.timeline_path(&timeline_id, &self.tenant_id);
+        if timeline_path.exists() {
+            bail!("Timeline directory already exists, but timeline is missing in repository map. This is a bug.")
+        }
 
         // Create the timeline directory, and write initial metadata to file.
-        crashsafe_dir::create_dir_all(self.conf.timeline_path(&timelineid, &self.tenant_id))?;
+        crashsafe_dir::create_dir_all(timeline_path)?;
 
         let metadata = TimelineMetadata::new(Lsn(0), None, None, Lsn(0), initdb_lsn, initdb_lsn);
-        Self::save_metadata(self.conf, timelineid, self.tenant_id, &metadata, true)?;
+        Self::save_metadata(self.conf, timeline_id, self.tenant_id, &metadata, true)?;
 
         let timeline = LayeredTimeline::new(
             self.conf,
             Arc::clone(&self.tenant_conf),
             metadata,
             None,
-            timelineid,
+            timeline_id,
             self.tenant_id,
             Arc::clone(&self.walredo_mgr),
             self.upload_layers,
@@ -257,12 +266,7 @@ impl Repository for LayeredRepository {
 
         // Insert if not exists
         let timeline = Arc::new(timeline);
-        match timelines.entry(timelineid) {
-            Entry::Occupied(_) => bail!("Timeline already exists"),
-            Entry::Vacant(vacant) => {
-                vacant.insert(LayeredTimelineEntry::Loaded(Arc::clone(&timeline)))
-            }
-        };
+        vacant_timeline_entry.insert(LayeredTimelineEntry::Loaded(Arc::clone(&timeline)));
 
         Ok(timeline)
     }

pageserver/src/repository.rs

@@ -225,7 +225,7 @@ pub trait Repository: Send + Sync {
     /// Initdb lsn is provided for timeline impl to be able to perform checks for some operations against it.
     fn create_empty_timeline(
         &self,
-        timelineid: ZTimelineId,
+        timeline_id: ZTimelineId,
         initdb_lsn: Lsn,
     ) -> Result<Arc<Self::Timeline>>;
 
@@ -636,6 +636,19 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn no_duplicate_timelines() -> Result<()> {
+        let repo = RepoHarness::create("no_duplicate_timelines")?.load();
+        let _ = repo.create_empty_timeline(TIMELINE_ID, Lsn(0))?;
+
+        match repo.create_empty_timeline(TIMELINE_ID, Lsn(0)) {
+            Ok(_) => panic!("duplicate timeline creation should fail"),
+            Err(e) => assert_eq!(e.to_string(), "Timeline already exists"),
+        }
+
+        Ok(())
+    }
+
     /// Convenience function to create a page image with given string as the only content
     pub fn test_value(s: &str) -> Value {
         let mut buf = BytesMut::new();

pageserver/src/storage_sync/download.rs

@@ -44,13 +44,23 @@ where
                 index_part_path.display()
             )
         })?;
+
+    let mut index_part_download =
+        storage
+            .download(&part_storage_path)
+            .await
+            .with_context(|| {
+                format!("Failed to open download stream for for storage path {part_storage_path:?}")
+            })?;
     let mut index_part_bytes = Vec::new();
-    storage
-        .download(&part_storage_path, &mut index_part_bytes)
-        .await
-        .with_context(|| {
-            format!("Failed to download an index part from storage path {part_storage_path:?}")
-        })?;
+    io::copy(
+        &mut index_part_download.download_stream,
+        &mut index_part_bytes,
+    )
+    .await
+    .with_context(|| {
+        format!("Failed to download an index part from storage path {part_storage_path:?}")
+    })?;
 
     let index_part: IndexPart = serde_json::from_slice(&index_part_bytes).with_context(|| {
         format!("Failed to deserialize index part file from storage path '{part_storage_path:?}'")
@@ -162,15 +172,19 @@ where
                             temp_file_path.display()
                         )
                     })?;
-
-                storage
-                    .download(&layer_storage_path, &mut destination_file)
+                let mut download = storage
+                    .download(&layer_storage_path)
                     .await
                     .with_context(|| {
                         format!(
-                            "Failed to download a layer from storage path '{layer_storage_path:?}'"
+                            "Failed to open a download stream for layer with remote storage path '{layer_storage_path:?}'"
                         )
                     })?;
+                io::copy(&mut download.download_stream, &mut destination_file).await.with_context(|| {
+                    format!(
+                        "Failed to download layer with remote storage path '{layer_storage_path:?}' into file '{}'", temp_file_path.display()
+                    )
+                })?;
 
                 // Tokio doc here: https://docs.rs/tokio/1.17.0/tokio/fs/struct.File.html states that:
                 // A file will not be closed immediately when it goes out of scope if there are any IO operations

safekeeper/src/wal_backup.rs

@@ -2,18 +2,16 @@ use anyhow::{Context, Result};
 use etcd_broker::subscription_key::{
     NodeKind, OperationKind, SkOperationKind, SubscriptionKey, SubscriptionKind,
 };
-use tokio::io::AsyncRead;
 use tokio::task::JoinHandle;
 
 use std::cmp::min;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
+use std::pin::Pin;
 use std::sync::Arc;
 use std::time::Duration;
 
-use postgres_ffi::xlog_utils::{
-    XLogFileName, XLogSegNo, XLogSegNoOffsetToRecPtr, MAX_SEND_SIZE, PG_TLI,
-};
+use postgres_ffi::xlog_utils::{XLogFileName, XLogSegNo, XLogSegNoOffsetToRecPtr, PG_TLI};
 use remote_storage::{GenericRemoteStorage, RemoteStorage};
 use tokio::fs::File;
 use tokio::runtime::Builder;
@@ -452,45 +450,41 @@ async fn backup_object(source_file: &Path, size: usize) -> Result<()> {
 pub async fn read_object(
     file_path: PathBuf,
     offset: u64,
-) -> (impl AsyncRead, JoinHandle<Result<()>>) {
-    let storage = REMOTE_STORAGE.get().expect("failed to get remote storage");
+) -> anyhow::Result<Pin<Box<dyn tokio::io::AsyncRead>>> {
+    let download = match REMOTE_STORAGE
+        .get()
+        .context("Failed to get remote storage")?
+        .as_ref()
+        .context("No remote storage configured")?
+    {
+        GenericRemoteStorage::Local(local_storage) => {
+            let source = local_storage.remote_object_id(&file_path)?;
 
-    let (mut pipe_writer, pipe_reader) = tokio::io::duplex(MAX_SEND_SIZE);
-
-    let copy_result = tokio::spawn(async move {
-        let res = match storage.as_ref().unwrap() {
-            GenericRemoteStorage::Local(local_storage) => {
-                let source = local_storage.remote_object_id(&file_path)?;
-
-                info!(
-                    "local download about to start from {} at offset {}",
-                    source.display(),
-                    offset
-                );
-                local_storage
-                    .download_byte_range(&source, offset, None, &mut pipe_writer)
-                    .await
-            }
-            GenericRemoteStorage::S3(s3_storage) => {
-                let s3key = s3_storage.remote_object_id(&file_path)?;
-
-                info!(
-                    "S3 download about to start from {:?} at offset {}",
-                    s3key, offset
-                );
-                s3_storage
-                    .download_byte_range(&s3key, offset, None, &mut pipe_writer)
-                    .await
-            }
-        };
-
-        if let Err(e) = res {
-            error!("failed to download WAL segment from remote storage: {}", e);
-            Err(e)
-        } else {
-            Ok(())
+            info!(
+                "local download about to start from {} at offset {}",
+                source.display(),
+                offset
+            );
+            local_storage
+                .download_byte_range(&source, offset, None)
+                .await
         }
-    });
+        GenericRemoteStorage::S3(s3_storage) => {
+            let s3key = s3_storage.remote_object_id(&file_path)?;
 
-    (pipe_reader, copy_result)
+            info!(
+                "S3 download about to start from {:?} at offset {}",
+                s3key, offset
+            );
+            s3_storage.download_byte_range(&s3key, offset, None).await
+        }
+    }
+    .with_context(|| {
+        format!(
+            "Failed to open WAL segment download stream for local storage path {}",
+            file_path.display()
+        )
+    })?;
+
+    Ok(download.download_stream)
 }

safekeeper/src/wal_storage.rs

@@ -604,8 +604,7 @@ impl WalReader {
 
         // Try to open remote file, if remote reads are enabled
         if self.enable_remote_read {
-            let (reader, _) = read_object(wal_file_path, xlogoff as u64).await;
-            return Ok(Box::pin(reader));
+            return read_object(wal_file_path, xlogoff as u64).await;
         }
 
         bail!("WAL segment is not found")

scripts/add_missing_rels.py

@@ -0,0 +1,438 @@
+import os
+import shutil
+from pathlib import Path
+import tempfile
+from contextlib import closing
+import psycopg2
+import subprocess
+import argparse
+
+### utils copied from test fixtures
+from typing import Any, List
+from psycopg2.extensions import connection as PgConnection
+import asyncpg
+from typing import Any, Callable, Dict, Iterator, List, Optional, TypeVar, cast, Union, Tuple
+
+Env = Dict[str, str]
+
+_global_counter = 0
+
+
+def global_counter() -> int:
+    """ A really dumb global counter.
+
+    This is useful for giving output files a unique number, so if we run the
+    same command multiple times we can keep their output separate.
+    """
+    global _global_counter
+    _global_counter += 1
+    return _global_counter
+
+
+def subprocess_capture(capture_dir: str, cmd: List[str], **kwargs: Any) -> str:
+    """ Run a process and capture its output
+
+    Output will go to files named "cmd_NNN.stdout" and "cmd_NNN.stderr"
+    where "cmd" is the name of the program and NNN is an incrementing
+    counter.
+
+    If those files already exist, we will overwrite them.
+    Returns basepath for files with captured output.
+    """
+    assert type(cmd) is list
+    base = os.path.basename(cmd[0]) + '_{}'.format(global_counter())
+    basepath = os.path.join(capture_dir, base)
+    stdout_filename = basepath + '.stdout'
+    stderr_filename = basepath + '.stderr'
+
+    with open(stdout_filename, 'w') as stdout_f:
+        with open(stderr_filename, 'w') as stderr_f:
+            print('(capturing output to "{}.stdout")'.format(base))
+            subprocess.run(cmd, **kwargs, stdout=stdout_f, stderr=stderr_f)
+
+    return basepath
+
+
+class PgBin:
+    """ A helper class for executing postgres binaries """
+    def __init__(self, log_dir: Path, pg_distrib_dir):
+        self.log_dir = log_dir
+        self.pg_bin_path = os.path.join(str(pg_distrib_dir), 'bin')
+        self.env = os.environ.copy()
+        self.env['LD_LIBRARY_PATH'] = os.path.join(str(pg_distrib_dir), 'lib')
+
+    def _fixpath(self, command: List[str]):
+        if '/' not in command[0]:
+            command[0] = os.path.join(self.pg_bin_path, command[0])
+
+    def _build_env(self, env_add: Optional[Env]) -> Env:
+        if env_add is None:
+            return self.env
+        env = self.env.copy()
+        env.update(env_add)
+        return env
+
+    def run(self, command: List[str], env: Optional[Env] = None, cwd: Optional[str] = None):
+        """
+        Run one of the postgres binaries.
+
+        The command should be in list form, e.g. ['pgbench', '-p', '55432']
+
+        All the necessary environment variables will be set.
+
+        If the first argument (the command name) doesn't include a path (no '/'
+        characters present), then it will be edited to include the correct path.
+
+        If you want stdout/stderr captured to files, use `run_capture` instead.
+        """
+
+        self._fixpath(command)
+        print('Running command "{}"'.format(' '.join(command)))
+        env = self._build_env(env)
+        subprocess.run(command, env=env, cwd=cwd, check=True)
+
+    def run_capture(self,
+                    command: List[str],
+                    env: Optional[Env] = None,
+                    cwd: Optional[str] = None,
+                    **kwargs: Any) -> str:
+        """
+        Run one of the postgres binaries, with stderr and stdout redirected to a file.
+
+        This is just like `run`, but for chatty programs. Returns basepath for files
+        with captured output.
+        """
+
+        self._fixpath(command)
+        print('Running command "{}"'.format(' '.join(command)))
+        env = self._build_env(env)
+        return subprocess_capture(str(self.log_dir),
+                                  command,
+                                  env=env,
+                                  cwd=cwd,
+                                  check=True,
+                                  **kwargs)
+
+class PgProtocol:
+    """ Reusable connection logic """
+    def __init__(self, **kwargs):
+        self.default_options = kwargs
+
+    def connstr(self, **kwargs) -> str:
+        """
+        Build a libpq connection string for the Postgres instance.
+        """
+        return str(make_dsn(**self.conn_options(**kwargs)))
+
+    def conn_options(self, **kwargs):
+        conn_options = self.default_options.copy()
+        if 'dsn' in kwargs:
+            conn_options.update(parse_dsn(kwargs['dsn']))
+        conn_options.update(kwargs)
+
+        # Individual statement timeout in seconds. 2 minutes should be
+        # enough for our tests, but if you need a longer, you can
+        # change it by calling "SET statement_timeout" after
+        # connecting.
+        if 'options' in conn_options:
+            conn_options['options'] = f"-cstatement_timeout=120s " + conn_options['options']
+        else:
+            conn_options['options'] = "-cstatement_timeout=120s"
+        return conn_options
+
+    # autocommit=True here by default because that's what we need most of the time
+    def connect(self, autocommit=True, **kwargs) -> PgConnection:
+        """
+        Connect to the node.
+        Returns psycopg2's connection object.
+        This method passes all extra params to connstr.
+        """
+        conn = psycopg2.connect(**self.conn_options(**kwargs))
+
+        # WARNING: this setting affects *all* tests!
+        conn.autocommit = autocommit
+        return conn
+
+    async def connect_async(self, **kwargs) -> asyncpg.Connection:
+        """
+        Connect to the node from async python.
+        Returns asyncpg's connection object.
+        """
+
+        # asyncpg takes slightly different options than psycopg2. Try
+        # to convert the defaults from the psycopg2 format.
+
+        # The psycopg2 option 'dbname' is called 'database' is asyncpg
+        conn_options = self.conn_options(**kwargs)
+        if 'dbname' in conn_options:
+            conn_options['database'] = conn_options.pop('dbname')
+
+        # Convert options='-c<key>=<val>' to server_settings
+        if 'options' in conn_options:
+            options = conn_options.pop('options')
+            for match in re.finditer('-c(\w*)=(\w*)', options):
+                key = match.group(1)
+                val = match.group(2)
+                if 'server_options' in conn_options:
+                    conn_options['server_settings'].update({key: val})
+                else:
+                    conn_options['server_settings'] = {key: val}
+        return await asyncpg.connect(**conn_options)
+
+    def safe_psql(self, query: str, **kwargs: Any) -> List[Tuple[Any, ...]]:
+        """
+        Execute query against the node and return all rows.
+        This method passes all extra params to connstr.
+        """
+        return self.safe_psql_many([query], **kwargs)[0]
+
+    def safe_psql_many(self, queries: List[str], **kwargs: Any) -> List[List[Tuple[Any, ...]]]:
+        """
+        Execute queries against the node and return all rows.
+        This method passes all extra params to connstr.
+        """
+        result: List[List[Any]] = []
+        with closing(self.connect(**kwargs)) as conn:
+            with conn.cursor() as cur:
+                for query in queries:
+                    print(f"Executing query: {query}")
+                    cur.execute(query)
+
+                    if cur.description is None:
+                        result.append([])  # query didn't return data
+                    else:
+                        result.append(cast(List[Any], cur.fetchall()))
+        return result
+
+
+class VanillaPostgres(PgProtocol):
+    def __init__(self, pgdatadir: Path, pg_bin: PgBin, port: int, init=True):
+        super().__init__(host='localhost', port=port, dbname='postgres')
+        self.pgdatadir = pgdatadir
+        self.pg_bin = pg_bin
+        self.running = False
+        if init:
+            self.pg_bin.run_capture(['initdb', '-D', str(pgdatadir)])
+        self.configure([f"port = {port}\n"])
+
+    def configure(self, options: List[str]):
+        """Append lines into postgresql.conf file."""
+        assert not self.running
+        with open(os.path.join(self.pgdatadir, 'postgresql.conf'), 'a') as conf_file:
+            conf_file.write("\n".join(options))
+
+    def start(self, log_path: Optional[str] = None):
+        assert not self.running
+        self.running = True
+
+        if log_path is None:
+            log_path = os.path.join(self.pgdatadir, "pg.log")
+
+        self.pg_bin.run_capture(
+            ['pg_ctl', '-w', '-D', str(self.pgdatadir), '-l', log_path, 'start'])
+
+    def stop(self):
+        assert self.running
+        self.running = False
+        self.pg_bin.run_capture(['pg_ctl', '-w', '-D', str(self.pgdatadir), 'stop'])
+
+    def get_subdir_size(self, subdir) -> int:
+        """Return size of pgdatadir subdirectory in bytes."""
+        return get_dir_size(os.path.join(self.pgdatadir, subdir))
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc, tb):
+        if self.running:
+            self.stop()
+
+
+### actual code
+
+
+def get_rel_paths(log_dir, pg_bin, base_tar):
+    """Yeild list of relation paths"""
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", base_tar, "-C", restored_dir])
+
+        port = "55439"  # Probably free
+        with VanillaPostgres(restored_dir, pg_bin, port, init=False) as vanilla_pg:
+            vanilla_pg.configure([f"port={port}"])
+            vanilla_pg.start()
+
+            # Create database based on template0 because we can't connect to template0
+            query = "create database template0copy template template0"
+            vanilla_pg.safe_psql(query, user="cloud_admin")
+            vanilla_pg.safe_psql("CHECKPOINT", user="cloud_admin")
+
+            # Get all databases
+            query = "select oid, datname from pg_database"
+            oid_dbname_pairs = vanilla_pg.safe_psql(query, user="cloud_admin")
+            template0_oid = [
+                oid
+                for (oid, database) in oid_dbname_pairs
+                if database == "template0"
+            ][0]
+
+            # Get rel paths for each database
+            for oid, database in oid_dbname_pairs:
+                if database == "template0":
+                    # We can't connect to template0
+                    continue
+
+                query = "select relname, pg_relation_filepath(oid) from pg_class"
+                result = vanilla_pg.safe_psql(query, user="cloud_admin", dbname=database)
+                for relname, filepath in result:
+                    if filepath is not None:
+
+                        if database == "template0copy":
+                            # Add all template0copy paths to template0
+                            prefix = f"base/{oid}/"
+                            if filepath.startswith(prefix):
+                                suffix = filepath[len(prefix):]
+                                yield f"base/{template0_oid}/{suffix}"
+                            elif filepath.startswith("global"):
+                                print(f"skipping {database} global file {filepath}")
+                            else:
+                                raise AssertionError
+                        else:
+                            yield filepath
+
+
+def pack_base(log_dir, restored_dir, output_tar):
+    tmp_tar_name = "tmp.tar"
+    tmp_tar_path = os.path.join(restored_dir, tmp_tar_name)
+    cmd = ["tar", "-cf", tmp_tar_name] + os.listdir(restored_dir)
+    subprocess_capture(log_dir, cmd, cwd=restored_dir)
+    shutil.move(tmp_tar_path, output_tar)
+
+
+def get_files_in_tar(log_dir, tar):
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", tar, "-C", restored_dir])
+
+        # Find empty files
+        empty_files = []
+        for root, dirs, files in os.walk(restored_dir):
+            for name in files:
+                file_path = os.path.join(root, name)
+                yield file_path[len(restored_dir) + 1:]
+
+
+def corrupt(log_dir, base_tar, output_tar):
+    """Remove all empty files and repackage. Return paths of files removed."""
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", base_tar, "-C", restored_dir])
+
+        # Find empty files
+        empty_files = []
+        for root, dirs, files in os.walk(restored_dir):
+            for name in files:
+                file_path = os.path.join(root, name)
+                file_size = os.path.getsize(file_path)
+                if file_size == 0:
+                    empty_files.append(file_path)
+
+        # Delete empty files (just to see if they get recreated)
+        for empty_file in empty_files:
+            os.remove(empty_file)
+
+        # Repackage
+        pack_base(log_dir, restored_dir, output_tar)
+
+        # Return relative paths
+        return {
+            empty_file[len(restored_dir) + 1:]
+            for empty_file in empty_files
+        }
+
+
+def touch_missing_rels(log_dir, corrupt_tar, output_tar, paths):
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", corrupt_tar, "-C", restored_dir])
+
+        # Touch files that don't exist
+        for path in paths:
+            absolute_path = os.path.join(restored_dir, path)
+            exists = os.path.exists(absolute_path)
+            if not exists:
+                print("File {absolute_path} didn't exist. Creating..")
+                Path(absolute_path).touch()
+
+        # Repackage
+        pack_base(log_dir, restored_dir, output_tar)
+
+
+# TODO this test is not currently called. It needs any ordinary base.tar path as input
+def test_add_missing_rels(base_tar):
+    output_tar = base_tar + ".fixed"
+
+    # Create new base tar with missing empty files
+    corrupt_tar = os.path.join(test_output_dir, "psql_2-corrupted.stdout")
+    deleted_files = corrupt(test_output_dir, base_tar, corrupt_tar)
+    assert len(set(get_files_in_tar(test_output_dir, base_tar)) -
+               set(get_files_in_tar(test_output_dir, corrupt_tar))) > 0
+
+    # Reconstruct paths from the corrupted tar, assert it covers everything important
+    reconstructed_paths = set(get_rel_paths(test_output_dir, pg_bin, corrupt_tar))
+    paths_missed = deleted_files - reconstructed_paths
+    assert paths_missed.issubset({
+        "postgresql.auto.conf",
+        "pg_ident.conf",
+    })
+
+    # Recreate the correct tar by touching files, compare with original tar
+    touch_missing_rels(test_output_dir, corrupt_tar, output_tar, reconstructed_paths)
+    paths_missed = (set(get_files_in_tar(test_output_dir, base_tar)) -
+                    set(get_files_in_tar(test_output_dir, output_tar)))
+    assert paths_missed.issubset({
+        "postgresql.auto.conf",
+        "pg_ident.conf",
+    })
+
+
+# Example command:
+# poetry run python scripts/add_missing_rels.py \
+#     --base-tar /home/bojan/src/neondatabase/neon/test_output/test_import_from_pageserver/psql_2.stdout \
+#     --output-tar output-base.tar \
+#     --log-dir /home/bojan/tmp
+#     --pg-distrib-dir /home/bojan/src/neondatabase/neon/tmp_install/
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '--base-tar',
+        dest='base_tar',
+        required=True,
+        help='base.tar file to add missing rels to (file will not be modified)',
+    )
+    parser.add_argument(
+        '--output-tar',
+        dest='output_tar',
+        required=True,
+        help='path and name for the output base.tar file',
+    )
+    parser.add_argument(
+        '--log-dir',
+        dest='log_dir',
+        required=True,
+        help='directory to save log files in',
+    )
+    parser.add_argument(
+        '--pg-distrib-dir',
+        dest='pg_distrib_dir',
+        required=True,
+        help='directory where postgres is installed',
+    )
+    args = parser.parse_args()
+    base_tar = args.base_tar
+    output_tar = args.output_tar
+    log_dir = args.log_dir
+    pg_bin = PgBin(log_dir, args.pg_distrib_dir)
+
+    reconstructed_paths = set(get_rel_paths(log_dir, pg_bin, base_tar))
+    touch_missing_rels(log_dir, base_tar, output_tar, reconstructed_paths)

scripts/export_import_betwen_pageservers.py

@@ -72,6 +72,14 @@ class NeonPageserverHttpClient(requests.Session):
         return res_json
 
 
+import pytest
+import os
+def add_missing_empty_rels(base_tar, output_tar):
+    os.environ['INPUT_BASE_TAR'] = base_tar
+    os.environ['OUTPUT_BASE_TAR'] = output_tar
+    pytest.main(["-s", "-k", "test_main_hack"])
+
+
 def main(args: argparse.Namespace):
     old_pageserver_host = args.old_pageserver_host
     new_pageserver_host = args.new_pageserver_host
@@ -102,7 +110,7 @@ def main(args: argparse.Namespace):
             if args.only_import is False:
                 query = f"fullbackup {timeline['tenant_id']} {timeline['timeline_id']} {timeline['local']['last_record_lsn']}"
 
-                cmd = ["psql", "--no-psqlrc", old_pageserver_connstr, "-c", query]
+                cmd = [args.psql_path, "--no-psqlrc", old_pageserver_connstr, "-c", query]
                 print(f"Running: {cmd}")
 
                 tar_filename = path.join(basepath,
@@ -115,6 +123,8 @@ def main(args: argparse.Namespace):
                         print(f"(capturing output to {tar_filename})")
                         subprocess.run(cmd, stdout=stdout_f, stderr=stderr_f, env=psql_env)
 
+                # add_missing_emtpy_rels(incomplete_tar_filename, tar_filename)
+
                 print(f"Done export: {tar_filename}")
 
             # Import timelines to new pageserver

test_runner/batch_others/test_complete_basebackup.py

@@ -0,0 +1,167 @@
+from fixtures.neon_fixtures import VanillaPostgres
+from fixtures.utils import subprocess_capture
+import os
+import shutil
+from pathlib import Path
+import tempfile
+
+
+def get_rel_paths(log_dir, pg_bin, base_tar):
+    """Yeild list of relation paths"""
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", base_tar, "-C", restored_dir])
+
+        port = "55439"  # Probably free
+        with VanillaPostgres(restored_dir, pg_bin, port, init=False) as vanilla_pg:
+            vanilla_pg.configure([f"port={port}"])
+            vanilla_pg.start()
+
+            # Create database based on template0 because we can't connect to template0
+            query = "create database template0copy template template0"
+            vanilla_pg.safe_psql(query, user="cloud_admin")
+            vanilla_pg.safe_psql("CHECKPOINT", user="cloud_admin")
+
+            # Get all databases
+            query = "select oid, datname from pg_database"
+            oid_dbname_pairs = vanilla_pg.safe_psql(query, user="cloud_admin")
+            template0_oid = [
+                oid
+                for (oid, database) in oid_dbname_pairs
+                if database == "template0"
+            ][0]
+
+            # Get rel paths for each database
+            for oid, database in oid_dbname_pairs:
+                if database == "template0":
+                    # We can't connect to template0
+                    continue
+
+                query = "select relname, pg_relation_filepath(oid) from pg_class"
+                result = vanilla_pg.safe_psql(query, user="cloud_admin", dbname=database)
+                for relname, filepath in result:
+                    if filepath is not None:
+
+                        if database == "template0copy":
+                            # Add all template0copy paths to template0
+                            prefix = f"base/{oid}/"
+                            if filepath.startswith(prefix):
+                                suffix = filepath[len(prefix):]
+                                yield f"base/{template0_oid}/{suffix}"
+                            elif filepath.startswith("global"):
+                                print(f"skipping {database} global file {filepath}")
+                            else:
+                                raise AssertionError
+                        else:
+                            yield filepath
+
+
+def pack_base(log_dir, restored_dir, output_tar):
+    tmp_tar_name = "tmp.tar"
+    tmp_tar_path = os.path.join(restored_dir, tmp_tar_name)
+    cmd = ["tar", "-cf", tmp_tar_name] + os.listdir(restored_dir)
+    subprocess_capture(log_dir, cmd, cwd=restored_dir)
+    shutil.move(tmp_tar_path, output_tar)
+
+
+def get_files_in_tar(log_dir, tar):
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", tar, "-C", restored_dir])
+
+        # Find empty files
+        empty_files = []
+        for root, dirs, files in os.walk(restored_dir):
+            for name in files:
+                file_path = os.path.join(root, name)
+                yield file_path[len(restored_dir) + 1:]
+
+
+def corrupt(log_dir, base_tar, output_tar):
+    """Remove all empty files and repackage. Return paths of files removed."""
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", base_tar, "-C", restored_dir])
+
+        # Find empty files
+        empty_files = []
+        for root, dirs, files in os.walk(restored_dir):
+            for name in files:
+                file_path = os.path.join(root, name)
+                file_size = os.path.getsize(file_path)
+                if file_size == 0:
+                    empty_files.append(file_path)
+
+        # Delete empty files (just to see if they get recreated)
+        for empty_file in empty_files:
+            os.remove(empty_file)
+
+        # Repackage
+        pack_base(log_dir, restored_dir, output_tar)
+
+        # Return relative paths
+        return {
+            empty_file[len(restored_dir) + 1:]
+            for empty_file in empty_files
+        }
+
+
+def touch_missing_rels(log_dir, corrupt_tar, output_tar, paths):
+    with tempfile.TemporaryDirectory() as restored_dir:
+        # Unpack the base tar
+        subprocess_capture(log_dir, ["tar", "-xf", corrupt_tar, "-C", restored_dir])
+
+        # Touch files that don't exist
+        for path in paths:
+            absolute_path = os.path.join(restored_dir, path)
+            exists = os.path.exists(absolute_path)
+            if not exists:
+                print("File {absolute_path} didn't exist. Creating..")
+                Path(absolute_path).touch()
+
+        # Repackage
+        pack_base(log_dir, restored_dir, output_tar)
+
+
+def test_complete(test_output_dir, pg_bin):
+    # Specify directories
+    # TODO make a basebackup instead of using one from another test
+    work_dir = "/home/bojan/src/neondatabase/neon/test_output/test_import_from_pageserver/"
+    base_tar = os.path.join(work_dir, "psql_2.stdout")
+    output_tar = os.path.join(work_dir, "psql_2-completed.stdout")
+
+    # Create new base tar with missing empty files
+    corrupt_tar = os.path.join(test_output_dir, "psql_2-corrupted.stdout")
+    deleted_files = corrupt(test_output_dir, base_tar, corrupt_tar)
+    assert len(set(get_files_in_tar(test_output_dir, base_tar)) -
+               set(get_files_in_tar(test_output_dir, corrupt_tar))) > 0
+
+    # Reconstruct paths from the corrupted tar, assert it covers everything important
+    reconstructed_paths = set(get_rel_paths(test_output_dir, pg_bin, corrupt_tar))
+    paths_missed = deleted_files - reconstructed_paths
+    assert paths_missed.issubset({
+        "postgresql.auto.conf",
+        "pg_ident.conf",
+    })
+
+    # Recreate the correct tar by touching files, compare with original tar
+    touch_missing_rels(test_output_dir, corrupt_tar, output_tar, reconstructed_paths)
+    paths_missed = (set(get_files_in_tar(test_output_dir, base_tar)) -
+                    set(get_files_in_tar(test_output_dir, output_tar)))
+    assert paths_missed.issubset({
+        "postgresql.auto.conf",
+        "pg_ident.conf",
+    })
+
+# HACK this script relies on test fixtures, but you can run it with
+# poetry run pytest -k test_main_hack and pass inputs via envvars
+#
+# The script takes a base tar, infers what empty rel files might be missing
+# and creates a new base tar with those files included. It does not modify
+# the original file.
+def test_main_hack(test_output_dir, pg_bin, pytestconfig):
+    base_tar = os.environ['INPUT_BASE_TAR']
+    output_tar = os.environ['OUTPUT_BASE_TAR']
+
+    reconstructed_paths = set(get_rel_paths(test_output_dir, pg_bin, base_tar))
+    touch_missing_rels(test_output_dir, base_tar, output_tar, reconstructed_paths)

test_runner/batch_others/test_tenant_relocation.py

@@ -11,7 +11,7 @@ import signal
 import pytest
 
 from fixtures.neon_fixtures import PgProtocol, PortDistributor, Postgres, NeonEnvBuilder, Etcd, NeonPageserverHttpClient, assert_local, wait_until, wait_for_last_record_lsn, wait_for_upload, neon_binpath, pg_distrib_dir
-from fixtures.utils import lsn_from_hex
+from fixtures.utils import lsn_from_hex, subprocess_capture
 
 
 def assert_abs_margin_ratio(a: float, b: float, margin_ratio: float):
@@ -101,10 +101,6 @@ def load(pg: Postgres, stop_event: threading.Event, load_ok_event: threading.Eve
     log.info('load thread stopped')
 
 
-@pytest.mark.skip(
-    reason=
-    "needs to replace callmemaybe call with better idea how to migrate timelines between pageservers"
-)
 @pytest.mark.parametrize('with_load', ['with_load', 'without_load'])
 def test_tenant_relocation(neon_env_builder: NeonEnvBuilder,
                            port_distributor: PortDistributor,
@@ -188,30 +184,38 @@ def test_tenant_relocation(neon_env_builder: NeonEnvBuilder,
                                new_pageserver_http_port,
                                neon_env_builder.broker):
 
-        # call to attach timeline to new pageserver
-        new_pageserver_http.timeline_attach(tenant, timeline)
-        # new pageserver should be in sync (modulo wal tail or vacuum activity) with the old one because there was no new writes since checkpoint
-        new_timeline_detail = wait_until(
-            number_of_iterations=5,
-            interval=1,
-            func=lambda: assert_local(new_pageserver_http, tenant, timeline))
+        # Migrate either by attacking from s3 or import/export basebackup
+        relocation_method = "import"
+        if relocation_method == "import":
+            scripts_dir = "/home/bojan/src/neondatabase/neon/scripts/"
+            cmd = [
+                "python",
+                os.path.join(scripts_dir, "export_import_betwen_pageservers.py"),
+                "--tenant-id", tenant.hex,
+                "--from-host", "localhost",
+                "--from-http-port", str(pageserver_http.port),
+                "--from-pg-port", str(env.pageserver.service_port.pg),
+                "--to-host", "localhost",
+                "--to-http-port", str(new_pageserver_http_port),
+                "--to-pg-port", str(new_pageserver_pg_port),
+                "--psql-path", os.path.join(pg_distrib_dir, "bin", "psql"),
+            ]
+            subprocess_capture(env.repo_dir, cmd, check=True)
+        elif relocation_method == "attach":
+            # call to attach timeline to new pageserver
+            new_pageserver_http.timeline_attach(tenant, timeline)
 
-        # when load is active these checks can break because lsns are not static
-        # so lets check with some margin
-        assert_abs_margin_ratio(lsn_from_hex(new_timeline_detail['local']['disk_consistent_lsn']),
-                                lsn_from_hex(timeline_detail['local']['disk_consistent_lsn']),
-                                0.03)
+            # new pageserver should be in sync (modulo wal tail or vacuum activity) with the old one because there was no new writes since checkpoint
+            new_timeline_detail = wait_until(
+                number_of_iterations=5,
+                interval=1,
+                func=lambda: assert_local(new_pageserver_http, tenant, timeline))
 
-        # callmemaybe to start replication from safekeeper to the new pageserver
-        # when there is no load there is a clean checkpoint and no wal delta
-        # needs to be streamed to the new pageserver
-        # TODO (rodionov) use attach to start replication
-        with pg_cur(PgProtocol(host='localhost', port=new_pageserver_pg_port)) as cur:
-            # "callmemaybe {} {} host={} port={} options='-c ztimelineid={} ztenantid={}'"
-            safekeeper_connstring = f"host=localhost port={env.safekeepers[0].port.pg} options='-c ztimelineid={timeline} ztenantid={tenant} pageserver_connstr=postgresql://no_user:@localhost:{new_pageserver_pg_port}'"
-            cur.execute("callmemaybe {} {} {}".format(tenant.hex,
-                                                      timeline.hex,
-                                                      safekeeper_connstring))
+            # when load is active these checks can break because lsns are not static
+            # so lets check with some margin
+            assert_abs_margin_ratio(lsn_from_hex(new_timeline_detail['local']['disk_consistent_lsn']),
+                                    lsn_from_hex(timeline_detail['local']['disk_consistent_lsn']),
+                                    0.03)
 
         tenant_pg.stop()