rust/neon
1
0
Fork 0
mirror of https://github.com/neondatabase/neon.git synced 2026-05-27 18:10:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

Improve comments, formatting around layer_removal_cs lock.

Browse Source
This commit is contained in:
Heikki Linnakangas
2022-12-20 01:52:50 +02:00
committed by Heikki Linnakangas
parent 9a049aa846
commit 43fd89eaa7
1 changed files with 32 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
pageserver/src/tenant.rs
View File

@@ -1295,26 +1295,41 @@ impl Tenant {
info!("waiting for timeline tasks to shutdown");
task_mgr::shutdown_tasks(None, Some(self.tenant_id), Some(timeline_id)).await;
// No timeout here, GC & Compaction should be responsive to the `TimelineState::Stopping` change.
info!("waiting for layer_removal_cs.lock()");
let layer_removal_guard = timeline.layer_removal_cs.lock().await;
info!("got layer_removal_cs.lock(), deleting layer files");
{
// Grab the layer_removal_cs lock, and actually perform the deletion.
//
// This lock prevents multiple concurrent delete_timeline calls from
// stepping on each other's toes, while deleting the files. It also
// prevents GC or compaction from running at the same time.
//
// Note that there are still other race conditions between
// GC, compaction and timeline deletion. GC task doesn't
// register itself properly with the timeline it's
// operating on. See
// https://github.com/neondatabase/neon/issues/2671
//
// No timeout here, GC & Compaction should be responsive to the
// `TimelineState::Stopping` change.
info!("waiting for layer_removal_cs.lock()");
let layer_removal_guard = timeline.layer_removal_cs.lock().await;
info!("got layer_removal_cs.lock(), deleting layer files");
// NB: storage_sync upload tasks that reference these layers have been cancelled
// by the caller.
// NB: storage_sync upload tasks that reference these layers have been cancelled
// by the caller.
let local_timeline_directory = self.conf.timeline_path(&timeline_id, &self.tenant_id);
// XXX make this atomic so that, if we crash-mid-way, the timeline won't be picked up
// with some layers missing.
std::fs::remove_dir_all(&local_timeline_directory).with_context(|| {
format!(
"Failed to remove local timeline directory '{}'",
local_timeline_directory.display()
)
})?;
info!("finished deleting layer files, releasing layer_removal_cs.lock()");
let local_timeline_directory = self.conf.timeline_path(&timeline_id, &self.tenant_id);
// XXX make this atomic so that, if we crash-mid-way, the timeline won't be picked up
// with some layers missing.
std::fs::remove_dir_all(&local_timeline_directory).with_context(|| {
format!(
"Failed to remove local timeline directory '{}'",
local_timeline_directory.display()
)
})?;
drop(layer_removal_guard);
info!("finished deleting layer files, releasing layer_removal_cs.lock()");
drop(layer_removal_guard);
}
// Remove the timeline from the map.
let mut timelines = self.timelines.lock().unwrap();