Re: CAN YOU TO CHECK THE LOAD_BALANCER CONFIGURATION ON RAC SERVER
Date: Tue, 26 Feb 2008 00:55:42 -0800 (PST)
Message-ID: <362085.13097.qm@web58812.mail.re1.yahoo.com>
Roberto
Further to Finn's point:
- the load balancer attempts to allocate new connections to the "least loaded"
instance
- however, the measurement of "load" on each node is not very subtle, and it
takes a while for the listener to be updated with it
- which means that if you have a rush of connections, they may ALL go to the
currently least loaded node (or if all nodes are the same, the first node in
the listener's list).
- Giving you a very unbalanced load (which will never be corrected until more
connections are made).
A very common "connection storm" is when starting up an app server; I found
that a load-balanced (9i) OC4J would routinely set up all its initial
connections on the same node. A similar situation and a workaround is mentioned
here:
http://preferisco.blogspot.com/2006/04/micro-partitioning-pooled-sessions-in.html.
Of course, if any of your connections terminate (for example, if your connection pool shrinks itself), you can also see a balanced load become unbalanced.
Regards Nigel
-- http://www.freelists.org/webpage/oracle-lReceived on Tue Feb 26 2008 - 02:55:42 CST