RedisMetricclient_backend_wait_time
Time spent waiting to obtain a connection from the pool
OpenTelemetry (1)Summary
Measures the time client threads or processes wait to acquire an available connection from the pool. Elevated wait times indicate connection pool exhaustion, where demand exceeds available connections. This metric is a leading indicator of connection pool sizing issues and correlates with application latency increases when pools are undersized for workload demands.
Interface Metrics (1)
OpenTelemetry
Technical Annotations (6)
Configuration Parameters (1)
max_connectionsTechnical References (5)
active queriesconceptPgBouncercomponentProxySQLcomponentHikariCPcomponentpgBouncercomponentRelated Insights (9)
When async endpoints make synchronous Redis calls, they hold connections longer than necessary while blocking the event loop, causing artificial connection pool exhaustion even when Redis server capacity is available.
High bolt connections combined with client backend wait time indicates connection pool exhaustion, causing clients to queue for available connections and degrading application response times.
High client_backend_wait_time combined with low client_backend_usage indicates application connection pool misconfiguration or excessive connection churn, even when database-side cloudsql_googleapis_com/database/network/connections appears normal.
When client_backend_create_time and client_backend_wait_time are elevated, new connections are queuing because the instance is saturated with connection requests. This often precedes connection pool exhaustion and instance instability.
Concurrent transaction count approaching or exceeding configured limits can lead to transaction queuing, increased latency, and eventual request rejection.
When cloudsql_googleapis_com/database/network/connections or cloudsql_googleapis_com/database/postgresql/num_backend approaches max_connections limit, new connection attempts will fail, causing application errors and service disruption.