Troubleshooting
Problem
This document can be used to identify a user flooding Enterprise Replication (ER) send/receive queues with transactions
Symptom
Several occasions when ER/CDR queues become 'flooded' with transactions, it is critical to identify the user(s) triggering Data Manipulation Language (DML) SQL statements which consume a lot of logical log area that can cause the DDR Block situation and hang the Informix instance.
Cause
A user triggered a huge transaction causing several logical logs to be filled and ER sync to hang.
Diagnosing The Problem
1. Look at 'onstat -g rqm sendq'
2. Check the progress table and look for the 'group id' with the largest bytes queued;
3. The 'group id' is really the 'replicate id';
4. Look for the replicate id from 'onstat -g cat' to find the table used in that replicate;
5. With the table partnum information, now you can use one of the following options to find the session id or userthread:
- onlog
- onstat -g opn
- sqltrace history
Looking 'onstat -g rcv full" from one of the target servers also lists replicated id's and bytes received.
2. Check the progress table and look for the 'group id' with the largest bytes queued;
3. The 'group id' is really the 'replicate id';
4. Look for the replicate id from 'onstat -g cat' to find the table used in that replicate;
5. With the table partnum information, now you can use one of the following options to find the session id or userthread:
- onlog
- onstat -g opn
- sqltrace history
Looking 'onstat -g rcv full" from one of the target servers also lists replicated id's and bytes received.
Resolving The Problem
After finding the user/session id, cancell the userthread/session causing the flood.
[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"ARM Category":[{"code":"a8m500000008cgqAAA","label":"High Availability-\u003EEnterprise Replication (ER\/CDR)"}],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Type":"MASTER"}]
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Document Information
Modified date:
12 February 2026
UID
swg21572991