Kbase P121084: How to transition a database using Fathom Replication 3.0A/10.0B
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
02/05/2008 |
|
Status: Verified
GOAL:
How to transition a database using Fathom Replication 3.0A/10.0B
GOAL:
How to make target database become source database
GOAL:
Can a target database become source database in case of a source database failure using Fathom Replication 3.0A
GOAL:
Generic steps to transition a target database
GOAL:
How to use the source database ai notes that have not yet been applied to target
GOAL:
How to use target when restart of source database shows corruption during roll back recovery
GOAL:
What to do when source database is not recoverable
FACT(s) (Environment):
All Supported Operating Systems
Fathom High Availability Replication 3.0A
Fathom High Availability Replication 10.0B
FIX:
When a source database shows corruption during roll back recovery, force into the source database, followed by break replication, dump and load the source and rebaseline replication target, is considered. This is strongly inadvisable.
When using Fathom Replication, the target database is still unaffected and can therefore be transitioned. The following outlines this generic procedure, please refer to the Fathom Replication User's Guide for specific information particularly for OpenEdge versions where this utility has been further enhanced.
Steps:
Presuming that the target database is still running, but the Server (RPLS) on source has stopped.
[TARGET]
1.) The Agent needs to be in Pre-Transition state, so verify the status of the RPLA either:
$ dsrutil target -C monitor
A. Replication agent status
" State: Pre Transition "
or parse the target.lg file for message:
RPLA 5: A TCP/IP failure has occurred. The Agent's will enter PRE-TRANSITION, waiting for connection from the Replication Server. (11699)
if the agent is NOT in Pre-Transition state, force this state as follows:
$ dsrutil target -C triggertransition agent
NOTE: The target database needs to still be online. You cannot trigger transition if the Replication Agent is still connected to the replication server.
2.) Depending on how far behind the target was from the source, you may want to roll forward ai files not already applied to the target database.
[source]:
get the current state of each source.an file
$ rfutil source -C aimage list
only ai files with Status = LOCKED & BUSY are relevant
[target]:
find the last ai file that was being applied
$ dsrutil target -C RECOVERY agent > recagent.out
The following information from 'recagent.out' is relevant to this Example:
Replication local agent information:
Last Block: Incomplete
ID of the last TX begin: 1634
ID of the last TX end: 1635
Time of last TX end: Thu Jan 12 13:16:08 2006
After Image File Number: 6
Completly Applied to Target: No
[target]:
roll forward ai notes before transitioning the target database
$ dsrutil target -C ApplyExtent source.a6
the target.lg file will show similar messages to the following upon sucessful completion:
RPLA 5: Application of Source database AI Extent source.a6 has begun.
RPLA 5: Retry transaction point located at dbkey 0 note type 13 updctr 0. (6806)
RPLA 5: Retry point located at dbkey 662272 note type 25 updctr 6. (6807)
RPLA 5: Source database AI Extent source.a6 has been applied to this database.
3.) Transition the target database, roll back recovery will be performed and then the target database will be shut down.
$ dsrutil target -C transition agent
4.) The target database is now a non-replication enabled database (ie a "normal" database) which can now be accessed and used to re-baseline replication.