From 4a0a9e748c3317d509f22d48b42a29c64533d434 Mon Sep 17 00:00:00 2001
From: Konstantin Knizhnik <knizhnik@garret.ru>
Date: Thu, 22 Apr 2021 17:48:51 +0300
Subject: [PATCH] Enable garbage collector

---
 pageserver/src/bin/pageserver.rs |  4 ++--
 pageserver/src/page_cache.rs     | 12 +++++++-----
 pageserver/src/walredo.rs        |  2 +-
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/pageserver/src/bin/pageserver.rs b/pageserver/src/bin/pageserver.rs
index 23e0d5e57b..035667d62d 100644
--- a/pageserver/src/bin/pageserver.rs
+++ b/pageserver/src/bin/pageserver.rs
@@ -19,8 +19,8 @@ use slog::Drain;
 
 use pageserver::{page_service, tui, zenith_repo_dir, PageServerConf};
 
-const DEFAULT_GC_HORIZON: u64 = 0; //64 * 1024 * 1024;
-const DEFAULT_GC_PERIOD_SEC: u64 = 1;
+const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
+const DEFAULT_GC_PERIOD_SEC: u64 = 10;
 
 fn main() -> Result<()> {
     let arg_matches = App::new("Zenith page server")
diff --git a/pageserver/src/page_cache.rs b/pageserver/src/page_cache.rs
index 21f794913d..0af7141712 100644
--- a/pageserver/src/page_cache.rs
+++ b/pageserver/src/page_cache.rs
@@ -1,9 +1,7 @@
 //
 // Page Cache holds all the different page versions and WAL records
 //
-// The Page Cache is a BTreeMap, keyed by the RelFileNode an blocknumber, and the LSN.
-// The BTreeMap is protected by a Mutex, and each cache entry is protected by another
-// per-entry mutex.
+// The Page Cache is currenusing RocksDB for storing wal records and full page images, keyed by the RelFileNode, blocknumber, and the LSN.
 //
 
 use crate::restore_local_repo::restore_timeline;
@@ -174,7 +172,8 @@ fn open_rocksdb(_conf: &PageServerConf, timelineid: ZTimelineId) -> rocksdb::DB
     opts.create_if_missing(true);
     opts.set_use_fsync(true);
     opts.set_compression_type(rocksdb::DBCompressionType::Lz4);
-    rocksdb::DB::open(&opts, &path).unwrap()
+	opts.create_missing_column_families(true);
+    rocksdb::DB::open_cf(&opts, &path, &[rocksdb::DEFAULT_COLUMN_FAMILY_NAME]).unwrap()
 }
 
 fn init_page_cache(conf: &PageServerConf, timelineid: ZTimelineId) -> PageCache {
@@ -218,7 +217,7 @@ fn init_page_cache(conf: &PageServerConf, timelineid: ZTimelineId) -> PageCache
 // stored directly in the cache entry in that you still need to run the WAL redo
 // routine to generate the page image.
 //
-#[derive(PartialEq, Eq, PartialOrd, Ord, Clone)]
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
 pub struct CacheKey {
     pub tag: BufferTag,
     pub lsn: u64,
@@ -430,6 +429,7 @@ impl PageCache {
 
                         // reconstruct most recent page version
                         if content.wal_record.is_some() {
+							trace!("Reconstruct most recent page {:?}", key);
                             // force reconstruction of most recent page version
                             self.reconstruct_page(key, content)?;
                         }
@@ -451,6 +451,7 @@ impl PageCache {
                                     minbuf.clear();
                                     minbuf.extend_from_slice(&k);
                                     let key = CacheKey::unpack(&mut minbuf);
+									trace!("Reconstruct horizon page {:?}", key);
                                     self.reconstruct_page(key, content)?;
                                 }
                             }
@@ -458,6 +459,7 @@ impl PageCache {
                         // remove records prior to horizon
                         minbuf.clear();
                         minkey.pack(&mut minbuf);
+						trace!("Delete records in range {:?}..{:?}", minkey, maxkey);
                         self.db.delete_range_cf(cf, &minbuf[..], &maxbuf[..])?;
 
                         maxkey = minkey;
diff --git a/pageserver/src/walredo.rs b/pageserver/src/walredo.rs
index 0fc9ae51e7..10fa9caf8e 100644
--- a/pageserver/src/walredo.rs
+++ b/pageserver/src/walredo.rs
@@ -213,7 +213,7 @@ fn handle_apply_request(
 
     let result;
 
-    debug!(
+    trace!(
         "applied {} WAL records in {} ms to reconstruct page image at LSN {:X}/{:X}",
         nrecords,
         duration.as_millis(),