Enterprise Replication
Answered: amber (hollow confidence) — SaTriGuy offers a plausible partial explanation (avoid switching ER log files more than once an hour because of per-switch cleanup overhead), which matches the symptom of the tape drive being overwhelmed, but does not explain the ~350 phantom idle sessions and is never confirmed by the original asker.
Advisory only.
Posted in 1999
Topics: High Availability & Replication
We are starting to set up Enterprise Replication with IDS and IWS 7.30.tc2 on NT 4.0 servers. We had three server participating in our replication scheme and things seemed to be going well, until... I came in after a weekend and the were no humans logged on, but there were 195 sessions running on one server and 153 on another. The server with 195 sessions was creating log entries so fast that the tape drive where the logs were being backed up could not keep up, thus locking up the database. Since there was no activity we have no idea what was being logged. There were about three replicates that we had active at the time and none of those tables had been updated in at least two days. Has anybody else had similar experiences? I took the ER class about a year ago, and strangely enough this never came up. The ER products looks like it will do what we need, it was even kinda neat when it was working. Once we get around a few of these issues I think it is a good choice. Informix tech support has not be able to help us, but I have not been available to work with them much recently. Thanks Shannon P.S. I know somebody make a product that will solve this problem, but this does nothing to help me, Informix said their product would work too and I believe that it will.
Shannon, Do you remember the case number? I'd like to review the case. This be a problem with the rate with which the log files switch. Generally with ER you want to try to avoid switching a log file more than once an hour as there is some cleanup work that occurs when the log file switches. >Subject: Enterprise Replication >From: "Shannon Sellers" <ssellers@spike.tot.dor.state.co.us> >Date: 1/13/99 9:04 AM Central Standard Time >Message-id: <77icl0$fi0@chronicle.concentric.net> > >We are starting to set up Enterprise Replication with IDS and IWS 7.30.tc2 >on NT 4.0 servers. We had three server participating in our replication >scheme and things seemed to be going well, until... > >I came in after a weekend and the were no humans logged on, but there were >195 sessions running on one server and 153 on another. The server with 195 >sessions was creating log entries so fast that the tape drive where the >logs were being backed up could not keep up, thus locking up the database. >Since there was no activity we have no idea what was being logged. There >were about three replicates that we had active at the time and none of those >tables had been updated in at least two days. > >Has anybody else had similar experiences? I took the ER class about a year >ago, and strangely enough this never came up. > >The ER products looks like it will do what we need, it was even kinda neat >when it was working. Once we get around a few of these issues I think it is >a good choice. > >Informix tech support has not be able to help us, but I have not been >available to work with them much recently. > >Thanks Shannon > >P.S. I know somebody make a product that will solve this problem, but this >does nothing to help me, Informix said their product would work too and I >believe that it will. Madison Pruet