Re: Need Input on Parallel Server
Date: 1996/01/29
Message-ID: <4ej2md$sme_at_madison.tdsnet.com>#1/1
bbap_at_aol.com (BBAP) wrote:
>We are considering using Parallel Server option for a large database with
>a very high transaction rate. We estimate that our (RAID 0+1) database
>will be about 50 - 70 Gb, and our transaction rate will be over 100 tps.
>
>We are looking at SUN PDB servers, and would like to get some input on
>experience people have with the parallel option.
>
>How stable, how easy to maintain, how is support, what problems have shown
>up, where are the limitations, etc.
>
>I appreciate your input...
>
>Thanks a million!!!
>
>Bernie
>bbap_at_aol.com
Bernie,
One limitation is the access of modified blocks by multiple nodes.
While the documentation points out that collisions (pings) occur when an instance reads a block for update that another instance has a "dirty" copy of. The collision results in a forced write of the dirty buffer and subsequent read by the requester.
This will also happen to support read consistency. In otherwords when an instance wants to read (no update) a block that is currently lock exclusively by another instance (dirty buffer) a forced write will occur.
It is important to insure that users from the different nodes are either accessing different data or primarly reading (no updates) shared data.
Ken F.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Received on Mon Jan 29 1996 - 00:00:00 CET