Re: HDR+Connection Manager in intermittent network scenario

Hi Nate, I guess the manual failover (DRAUTO=0) is the best configuration for HADR and CM environment for handling the conditions described by you in you mail below. (dealing with network issues) Hi Cesar, This look like a little different behavior than in the earlier version (I guess it was 11.50.FC5) something. In that version the DRAUTO=0 with FOC ON was the only way I could get failover to work properly, but what you described below looks very different. Thanks & Regards, Pravin From: Cesar Inacio Martins <cesar_inacio_martins@yahoo.com.br> To: informix-list@iiug.org Date: 12/08/2010 11:29 PM Subject: Re: HDR+Connection Manager in intermittent network scenario Sent by: informix-list-bounces@iiug.org Nate, you will found information about this on the manuals. Check for DRAUTO, FAILOVER_CALLBACK... Just sharing a issues what I got with IFX 11.50 FC7W1GE + CM 3.50 FC7, Linux. On environment with similar configuration, using HDR, I have trouble with CM FOC and DRAUTO configuration. Situations like, if primary fail, and back later, they don't detect the secondary is take over and mess all configuration. (configuring DRAUTO = 0 or 3 , just don't work what I expected...) The unique configuration what I found to work with HDR with out need to remake the "lost instance" is DRAUTO=1 and for this I need to disabling the FOC on CM. With DRAUTO=1 and FOC=disabled, On my tests, if the primary goes down, the secondary take over (new primary) immediately, when the original primary comeback , them automatically resynchronize and the back to original configuration. All other configurations (I try a lot), always something happen, the "lost instance" don't recognize the new primary or they don't synchronize or they just don't goes up or goes up in standard mode (the worst situation).... I still not sure if I missing something when I try to configure this environment or if this is the default behave with used HDR with CM FOC (don't detect the primary is back and treat the situation). Just for curiosity, with this same IFX version, onto other environment, using *SDS*, all works fine with CM. All switchover and identification of the new primary by the old primary or others secondaries... Regards Cesar On 12/03/2010 07:46 PM, Nate Woodward wrote: > I'm trying to acheive high availability without data loss. I have an HDR > pair configured with a connection manager on each box for redundancy. > Clients are pointed at an sqlhosts group with the connection managers in > them, and the connection managers are configured to redirect the clients > to the current primary server in the pair. The connection managers are > also configured for failover, with FOC = HDR,10, so that the secondary > takes over the primary's job if it fails. > > Now, I'm worried about this scenario: > - primary gets disconnected from network > - secondary is brought to primary mode > - primary regains network connectivity > - two primary's are on the network -- what now? > > I'm considering writing an ALARMPROGRAM script to bring down the primary > if it loses network connectivity, so that HDR can be re-established with > the old secondary as the new primary. Is there a better way to do what > I'm trying to accomplish? > > More info: > > Informix 11.70.UC1GE (Linux 32-bit, although it'll be 64-bit in > production if I get a working setup) > > sqlhosts (same on both boxes): > > barmgr group - - > primbar1 onsoctcp host1 foobar_1526 g=barmgr > primbar2 onsoctcp host2 foobar_1526 g=barmgr > > barcluster group - - i=10 > #foobar onsoctcp host1 foobar_1526> g=barcluster > foobar1 onsoctcp host1 foobar1_1527 g=barcluster > foobar2 onsoctcp host2 foobar2_1528 g=barcluster > > > > cmsm.cfg on host1: > > NAME barmgr1 > SLA primbar1=primary > DEBUG 1 > LOGFILE connmgr.log > FOC HDR,10 > > > > cmsm.cfg on host2: > > NAME barmgr2 > SLA primbar2=primary > DEBUG 1 > LOGFILE connmgr.log > FOC HDR,10 > > > > 'onstat -g dri' on host1: > > IBM Informix Dynamic Server Version 11.70.UC1GE -- On-Line (Prim) -- Up > 02:23:24 -- 354840 Kbytes> > Data Replication at 0x841a81a0: > Type State Paired server Last DR CKPT (id/pg) > Supports Proxy Writes > primary on foobar2 417 / 40 > NA > > DRINTERVAL -1 > DRTIMEOUT 30 > DRAUTO 3 > DRLOSTFOUND /usr/informix/etc/dr.lostfound > DRIDXAUTO 1 > ENCRYPT_HDR 0 > Backlog 0> > > > 'onstat -g dri' on host2: > > IBM Informix Dynamic Server Version 11.70.UC1GE -- Read-Only (Sec) -- Up > 01:46:53 -- 354840 Kbytes> > Data Replication at 0x841ae1a0: > Type State Paired server Last DR CKPT (id/pg) > Supports Proxy Writes > HDR Secondary on foobar1 417 / 40 > N > > DRINTERVAL -1 > DRTIMEOUT 30 > DRAUTO 3 > DRLOSTFOUND /usr/informix/etc/dr.lostfound > DRIDXAUTO 1 > ENCRYPT_HDR 0 > Backlog 0> > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list _______________________________________________ Informix-list mailing list Informix-list@iiug.org http://www.iiug.org/mailman/listinfo/informix-list