Torsten Schulz wrote:
Yes, I know: very difficult question, but I don't know what to do now.
Our Server: Dual-CPU with 1.2 GHz 1.5 GB RAM
Our Problem: We are a Community. Between 19 and 21 o clock we have >350 User in the Community. But then, the Database are very slow. And we have per CPU ~20-30% idle-time.
May we know the postgres version that you are running and see the query that run slow ?
Postgres: 7.3.2 Query: All queries
max_connections = 1000 # Must be, if lower then 500 we become connection-errors
shared_buffers = 5000 # 2*max_connections, min 16
max_fsm_relations = 1000 # min 10, fsm is free space map
max_fsm_pages = 2000000 # min 1000, fsm is free space map
max_locks_per_transaction = 64 # min 10
wal_buffers = 2000 # min 4
sort_mem = 32768 # min 32 vacuum_mem = 32768 # min 1024
fsync = false
enable_seqscan = true enable_indexscan = true enable_tidscan = true enable_sort = true enable_nestloop = true enable_mergejoin = true enable_hashjoin = true
effective_cache_size = 96000 # default in 8k pages
That are all uncommented lines. I've found the values in internet and had tested it. But in performance are no difference between old configuration an this.
I'll show tomorrow for this, today it is too late, the performance is now perfect. It's only slow on this 2 hours with so many users on server.Is also usefull take a look at your postgresql configuration. You can see doing select * from pg_stat_activity the queries that are currently running on your server, and do a explain analize on it to see which one is the bottleneck. If you are running the 7.4 you can see on the log the total ammount for each query.
Oh, and i can't update to 7.4. The Chat don't run with libraries of 7.4
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