fix: demote warnings, fix flakyness (#4837)

`WARN ... found future (image|delta) layer` are not actionable log
lines. They don't need to be warnings. `info!` is enough.

This also fixes some known but not tracked flakyness in
[`test_remote_timeline_client_calls_started_metric`][evidence].

[evidence]:
https://neon-github-public-dev.s3.amazonaws.com/reports/pr-4829/5683495367/index.html#/testresult/34fe79e24729618b

Closes #3369.
Closes #4473.

pageserver/src/tenant/timeline.rs

@@ -1600,7 +1600,7 @@ impl Timeline {
             if let Some(imgfilename) = ImageFileName::parse_str(&fname) {
                 // create an ImageLayer struct for each image file.
                 if imgfilename.lsn > disk_consistent_lsn {
-                    warn!(
+                    info!(
                         "found future image layer {} on timeline {} disk_consistent_lsn is {}",
                         imgfilename, self.timeline_id, disk_consistent_lsn
                     );
@@ -1632,7 +1632,7 @@ impl Timeline {
                 // is 102, then it might not have been fully flushed to disk
                 // before crash.
                 if deltafilename.lsn_range.end > disk_consistent_lsn + 1 {
-                    warn!(
+                    info!(
                         "found future delta layer {} on timeline {} disk_consistent_lsn is {}",
                         deltafilename, self.timeline_id, disk_consistent_lsn
                     );
@@ -1774,7 +1774,7 @@ impl Timeline {
             match remote_layer_name {
                 LayerFileName::Image(imgfilename) => {
                     if imgfilename.lsn > up_to_date_disk_consistent_lsn {
-                        warn!(
+                        info!(
                         "found future image layer {} on timeline {} remote_consistent_lsn is {}",
                         imgfilename, self.timeline_id, up_to_date_disk_consistent_lsn
                     );
@@ -1799,7 +1799,7 @@ impl Timeline {
                     // is 102, then it might not have been fully flushed to disk
                     // before crash.
                     if deltafilename.lsn_range.end > up_to_date_disk_consistent_lsn + 1 {
-                        warn!(
+                        info!(
                             "found future delta layer {} on timeline {} remote_consistent_lsn is {}",
                             deltafilename, self.timeline_id, up_to_date_disk_consistent_lsn
                         );

test_runner/regress/test_gc_cutoff.py

@@ -14,10 +14,6 @@
 def test_gc_cutoff(neon_env_builder: NeonEnvBuilder, pg_bin: PgBin):
     env = neon_env_builder.init_start()
 
-    # These warnings are expected, when the pageserver is restarted abruptly
-    env.pageserver.allowed_errors.append(".*found future image layer.*")
-    env.pageserver.allowed_errors.append(".*found future delta layer.*")
-
     pageserver_http = env.pageserver.http_client()
 
     # Use aggressive GC and checkpoint settings, so that we also exercise GC during the test

test_runner/regress/test_pageserver_restart.py

@@ -72,10 +72,6 @@ def test_pageserver_restart(neon_env_builder: NeonEnvBuilder):
 def test_pageserver_chaos(neon_env_builder: NeonEnvBuilder):
     env = neon_env_builder.init_start()
 
-    # These warnings are expected, when the pageserver is restarted abruptly
-    env.pageserver.allowed_errors.append(".*found future image layer.*")
-    env.pageserver.allowed_errors.append(".*found future delta layer.*")
-
     # Use a tiny checkpoint distance, to create a lot of layers quickly.
     # That allows us to stress the compaction and layer flushing logic more.
     tenant, _ = env.neon_cli.create_tenant(

test_runner/regress/test_recovery.py

@@ -15,10 +15,6 @@ def test_pageserver_recovery(neon_env_builder: NeonEnvBuilder):
     env = neon_env_builder.init_start()
     env.pageserver.is_testing_enabled_or_skip()
 
-    # These warnings are expected, when the pageserver is restarted abruptly
-    env.pageserver.allowed_errors.append(".*found future delta layer.*")
-    env.pageserver.allowed_errors.append(".*found future image layer.*")
-
     # Create a branch for us
     env.neon_cli.create_branch("test_pageserver_recovery", "main")
 

test_runner/regress/test_remote_storage.py

@@ -348,9 +348,6 @@ def churn_while_failpoints_active(result):
     # XXX: should vary this test to selectively fail just layer uploads, index uploads, deletions
     #      but how do we validate the result after restore?
 
-    # these are always possible when we do an immediate stop. perhaps something with compacting has changed since.
-    env.pageserver.allowed_errors.append(r".*found future (delta|image) layer.*")
-
     env.pageserver.stop(immediate=True)
     env.endpoints.stop_all()