Re: Low Performance for big hospital server ..

amrit@health2.moph.go.th wrote:

>>>max_connections = 160
>>>shared_buffers =  2048      [Total = 2.5 Gb.]
>>>sort_mem  = 8192   [Total = 1280 Mb.]
>>>vacuum_mem = 16384
>>>effective_cache_size  = 128897 [= 1007 Mb. = 1 Gb.  ]
>>>Will it be more suitable for my server than before?
>>>
>>>
>>>
>>>
>>>
>>>
>>I would keep shared_buffers in the 10000->20000 range, as this is
>>allocated *once* into shared memory, so only uses 80->160 Mb in *total*.
>>
>>
>
>You mean that if I increase the share buffer to arround 12000 [160 comnnections
>] , this will not affect the mem. usage ?
>
>
>
shared_buffers = 12000 will use 12000*8192 bytes (i.e about 96Mb). It is
shared, so no matter how many connections you have it will only use 96M.


>>The lower sort_mem will help reduce memory pressure (as this is
>>allocated for every backend connection) and this will help performance -
>>*unless* you have lots of queries that need to sort large datasets. If
>>so, then these will hammer your i/o subsystem, possibly canceling any
>>gain from freeing up more memory. So there is a need to understand what
>>sort of workload you have!
>>
>>
>
>Will the increasing in effective cache size to arround 200000 make a little bit
>improvement ? Do you think so?
>
>
>
I would leave it at the figure you proposed (128897), and monitor your
performance.
(you can always increase it later and see what the effect is).

regards

Mark