fix(pageserver): increase frozen layer warning threshold; ignore in t…

…ests (#9705)

Perf benchmarks produce a lot of layers.

## Summary of changes

Bumping the threshold and ignore the warning.

---------

Signed-off-by: Alex Chi Z <chi@neon.tech>

pageserver/src/tenant/timeline.rs

@@ -3531,7 +3531,7 @@ impl Timeline {
                         self.get_compaction_threshold(),
                         DEFAULT_COMPACTION_THRESHOLD,
                     )
-                    && frozen_layer_total_size >= /* 64 MB */ 64000000
+                    && frozen_layer_total_size >= /* 128 MB */ 128000000
                 {
                     tracing::warn!(
                         "too many frozen layers: {num_frozen_layers} layers with estimated in-mem size of {frozen_layer_total_size} bytes",

test_runner/fixtures/pageserver/allowed_errors.py

@@ -93,6 +93,8 @@ def scan_pageserver_log_for_errors(
     ".*WARN.*path=/v1/utilization .*request was dropped before completing",
     # Can happen during shutdown
     ".*scheduling deletion on drop failed: queue is in state Stopped.*",
+    # Too many frozen layers error is normal during intensive benchmarks
+    ".*too many frozen layers.*",
 )