Technologies/PostgreSQL/buffers_clean
PostgreSQLPostgreSQLMetric

buffers_clean

Buffers written by bgwriter
Dimensions:None
Available on:DatadogDatadog (1)Native (1)PrometheusPrometheus (1)
Interface Metrics (3)
DatadogDatadog
The number of buffers written by the background writer.
Dimensions:None
Native
Number of buffers written by background writer
Dimensions:None
PrometheusPrometheus
Number of buffers written by the background writer
Dimensions:None
Sources
postgresql.bgwriter.buffers_cleangithub.com
buffers_cleangithub.com
stat_bgwriter_buffers_clean_totalgithub.com

Technical Annotations (8)

Configuration Parameters (5)
bgwriter_lru_maxpages
Maximum buffers background writer can write per round
bgwriter_lru_multiplier
Multiplier for background writer activity
checkpoint_timeout
Time between automatic checkpoints
max_wal_size
Maximum WAL size before checkpoint
shared_buffers
CLI Commands (2)
gcloud sql instances patch INSTANCE_NAME --database-flags=checkpoint_timeout=900Attempt to set checkpoint timeout (may be silently capped or rejected)
SELECT checkpoints_timed, checkpoints_req, buffers_checkpoint, buffers_clean FROM pg_stat_bgwriter;Monitor checkpoint behavior to verify if tuning changes took effect
Technical References (1)
pg_stat_bgwritercomponent
Related Insights (2)
Background writer cannot keep up with I/O demandwarning
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Cloud SQL flag restrictions prevent PostgreSQL checkpoint tuning for write workloadswarning

Cloud SQL restricts modification of critical PostgreSQL checkpoint parameters (checkpoint_timeout, max_wal_size) to prevent storage issues. This prevents standard PostgreSQL tuning for write-heavy workloads, causing frequent checkpoint I/O spikes that would normally be mitigated by extending checkpoint intervals.

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