rust/neon
1
0
Fork 0
mirror of https://github.com/neondatabase/neon.git synced 2026-06-05 06:20:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

pageserver: remove defunct local timeline delete markers (#5699)

Browse Source 
## Problem

Historically, we treated the presence of a timeline on local disk as
evidence that it logically exists. Since #5580 that is no longer the
case, so we can always rely on remote storage. If we restart and the
timeline is gone in remote storage, we will also purge it from local
disk: no need for a marker.

Reference on why this PR is for timeline markers and not tenant markers:
https://github.com/neondatabase/neon/issues/5080#issuecomment-1783187807

## Summary of changes

Remove code paths that read + write deletion marker for timelines.

Leave code path that deletes these markers, just in case we deploy while
there are some in existence. This can be cleaned up later.
(https://github.com/neondatabase/neon/issues/5718)
This commit is contained in:
John Spray
2023-11-27 09:31:20 +00:00
committed by GitHub
parent 87b8ac3ec3
commit b80b9e1c4c
1 changed files with 2 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
pageserver/src/tenant/timeline/delete.rs
View File

@@ -110,35 +110,6 @@ async fn set_deleted_in_remote_index(timeline: &Timeline) -> Result<(), DeleteTi
Ok(())
}
// We delete local files first, so if pageserver restarts after local files deletion then remote deletion is not continued.
// This can be solved with inversion of these steps. But even if these steps are inverted then, when index_part.json
// gets deleted there is no way to distinguish between "this timeline is good, we just didnt upload it to remote"
// and "this timeline is deleted we should continue with removal of local state". So to avoid the ambiguity we use a mark file.
// After index part is deleted presence of this mark file indentifies that it was a deletion intention.
// So we can just remove the mark file.
async fn create_delete_mark(
conf: &PageServerConf,
tenant_id: TenantId,
timeline_id: TimelineId,
) -> Result<(), DeleteTimelineError> {
fail::fail_point!("timeline-delete-before-delete-mark", |_| {
Err(anyhow::anyhow!(
"failpoint: timeline-delete-before-delete-mark"
))?
});
let marker_path = conf.timeline_delete_mark_file_path(tenant_id, timeline_id);
// Note: we're ok to replace existing file.
let _ = std::fs::OpenOptions::new()
.write(true)
.create(true)
.open(&marker_path)
.with_context(|| format!("could not create delete marker file {marker_path:?}"))?;
crashsafe::fsync_file_and_parent(&marker_path).context("sync_mark")?;
Ok(())
}
/// Grab the layer_removal_cs lock, and actually perform the deletion.
///
/// This lock prevents prevents GC or compaction from running at the same time.
@@ -311,6 +282,8 @@ async fn cleanup_remaining_timeline_fs_traces(
.context("fsync_pre_mark_remove")?;
// Remove delete mark
// TODO: once we are confident that no more exist in the field, remove this
// line. It cleans up a legacy marker file that might in rare cases be present.
tokio::fs::remove_file(conf.timeline_delete_mark_file_path(tenant_id, timeline_id))
.await
.or_else(fs_ext::ignore_not_found)
@@ -391,8 +364,6 @@ impl DeleteTimelineFlow {
set_deleted_in_remote_index(&timeline).await?;
create_delete_mark(tenant.conf, timeline.tenant_id, timeline.timeline_id).await?;
fail::fail_point!("timeline-delete-before-schedule", |_| {
Err(anyhow::anyhow!(
"failpoint: timeline-delete-before-schedule"
@@ -464,10 +435,6 @@ impl DeleteTimelineFlow {
guard.mark_in_progress()?;
// Note that delete mark can be missing on resume
// because we create delete mark after we set deleted_at in the index part.
create_delete_mark(tenant.conf, tenant.tenant_id, timeline_id).await?;
Self::schedule_background(guard, tenant.conf, tenant, timeline);
Ok(())