SQLHOSTS for HDR
Jacob Shadix asked about the benefits of defining groups in sqlhosts for an HDR pair. Stuart Stephens used groups only in clients. Rafael Gomez said ER requires server groups, and with HDR clients connecting to the group try the primary and then the secondary. Madison Pruet said clients connecting to a group reach the current primary.
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What are the benefits to defining groups in sqlhosts for an HDR pair? I have had some issues with multiple instances (each with an HDR secondary on a separate server) where I left the group definitions out and came across some unexpected behavior when dealing with failover. After I put the group definitions back into the sqlhosts; all seemed to work normally. How would this affect normal operation if I am not using the HDR group names in any connection string?
I have never used group names in sqlhosts on the servers. I have used them in clients so they can connect to a group rather than an individual instance name.
Hi Jacob. Enterprise Replication requires that all database servers participating in replication be members of database server groups. So, if you are combining Enterprise Replication with HDR, both the primary and secondary HDR servers must be members of the same database server group The advantage of using groups in a pure HDR (no ER servers) consists in make client connections to group name (INFORMIXSERVER=group), then client will try to connect to primary and if it's not possible, conenct to secondary. Without no group definition your clients only will try connection to INFORMIXSERVER specified on each of them.
If you place the primary and secondary servers within a group, and your= client programs connect to the group instead of the server, then the cl= ient programs will end up connecting to the current primary server. M.P. From: "JACOB SHADIX" <jacobshadix@gmail.com> To: ids@iiug.org Date: 10/09/2014 09:45 PM Subject: SQLHOSTS for HDR [33955] Sent by: ids-bounces@iiug.org What are the benefits to defining groups in sqlhosts for an HDR pair? I= have had some issues with multiple instances (each with an HDR secondary on = a separate server) where I left the group definitions out and came across= some unexpected behavior when dealing with failover. After I put the group definitions back into the sqlhosts; all seemed to work normally. How wo= uld this affect normal operation if I am not using the HDR group names in a= ny connection string? ***********************************************************************= ******** Forum Note: Use "Reply" to post a response in the discussion forum. =