Martin Alderson (JIRA) wrote:
New replicas may never be synchronised
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Key: DIRSERVER-1098
URL: https://issues.apache.org/jira/browse/DIRSERVER-1098
Project: Directory ApacheDS
Issue Type: Bug
Components: mitosis
Affects Versions: 1.5.1
Reporter: Martin Alderson
Assignee: Martin Alderson
Priority: Minor
When the currently running replicas no longer have the original
modification
logs and a new replica is added and then modified before it has been brought
up to date then it will never be brought up to date.
I am currently testing a fix for this which will disallow all
modifications
to the new replica until it has been brought up to date.
Is there a doc somewhere that describes the replication protocol?
We encountered similar issues when developing the multimaster support in
OpenLDAP. Our solution was simply to assign unique server IDs to each master,
and record the last known modification for each known server ID. This way
local modifications don't overwrite the (lack of) state from other servers.
Another issue to consider when bringing up a new replica - you may want to
disallow all queries completely, until the replica has fully sync'd up. If you
allow searches during this initial phase, a client is likely to get a partial
set of results. In some cases, that may be worse than getting no result...
--
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/
