PostgreSQLFlexPGBouncer — PgBouncer Logs

The log stream of the built-in PgBouncer connection pooler. Only emitted when PgBouncer is enabled on the Flexible Server. One record per log line.

Kusto query

let server = "my-pg-prd-1";
AzureDiagnostics
| where Category == "PostgreSQLFlexPGBouncer" and LogicalServerName_s == server
| project log_s, source_s

Fields

• log_s (string) — the raw PgBouncer log line (timestamp, PID, level, message).
• source_s (string) — log source/stream (e.g. stderr).

Use cases — troubleshooting

• Pooler-level connection rejections — clients refused at PgBouncer before reaching Postgres (no more connections allowed, pool full).
• Pool exhaustion / queuing — pool_size reached, clients waiting for a server connection.
• Auth failures at the pooler — login failures handled by PgBouncer (separate from engine pg_hba errors).
• Client/server churn — frequent connect/disconnect, timeouts (client_idle_timeout, server_idle_timeout).
• Pooler restarts / config reloads — confirm PgBouncer (re)started or reloaded settings.
• Why connections "vanish" — distinguish pooler-side drops from engine-side drops.