Hello I have a report of critical bug (database is temporary unavailability .. restart is necessary).
A customer use: PostgreSQL 9.2.4, 24 CPU 140G RAM SSD disc for all Database is under high load. There is a few databases with very high number of similar simple statements. When application produce higher load, then number of active connection is increased to 300-600 about. In some moment starts described event - there is a minimal IO, all CPU are on 100%. Perf result shows: 354246.00 93.0% s_lock /usr/lib/postgresql/9.2/bin/postgres 10503.00 2.8% LWLockRelease /usr/lib/postgresql/9.2/bin/postgres 8802.00 2.3% LWLockAcquire /usr/lib/postgresql/9.2/bin/postgres 828.00 0.2% _raw_spin_lock [kernel.kallsyms] 559.00 0.1% _raw_spin_lock_irqsave [kernel.kallsyms] 340.00 0.1% switch_mm [kernel.kallsyms] 305.00 0.1% poll_schedule_timeout [kernel.kallsyms] 274.00 0.1% native_write_msr_safe [kernel.kallsyms] 257.00 0.1% _raw_spin_lock_irq [kernel.kallsyms] 238.00 0.1% apic_timer_interrupt [kernel.kallsyms] 236.00 0.1% __schedule [kernel.kallsyms] 213.00 0.1% HeapTupleSatisfiesMVCC We try to limit a connection to 300, but I am not sure if this issue is not related to some Postgres bug. Regards Pavel