Details
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Bug
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Status: Closed (View Workflow)
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Minor
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Resolution: Fixed
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1.4.3
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None
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2016-17
Description
Hi,
When the mmmon monitor detects multiple masters, the last master is always used by readconnroute:
[Core01 Master read-write Service]
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type=service
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router=readconnroute
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servers=core01,core11
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user=maxscale
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passwd=***
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router_options=master
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weightby=masterweight
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|
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[core01]
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type=server
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address=customer-prod-db-core01
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port=3306
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protocol=MySQLBackend
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masterweight=1
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|
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[core11]
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type=server
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address=customer-prod-db-core11
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port=3306
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protocol=MySQLBackend
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masterweight=0
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Two masters can be achieved by (incorrectly) disabling read_only on 2 nodes:
[root@leo-mt-prod-db-maxscale01 ~]# maxadmin -pmariadb show servers
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Server 0x2180ad0 (core01)
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Server: customer-prod-db-core01
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Status: Master, Running
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Protocol: MySQLBackend
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Port: 3306
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Node Id: 3
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Master Id: 11
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Repl Depth: 0
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Number of connections: 0
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Current no. of conns: 0
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Current no. of operations: 0
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Server 0x2180930 (core11)
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Server: customer-prod-db-core11
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Status: Master, Running
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Protocol: MySQLBackend
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Port: 3306
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Node Id: 11
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Master Id: 3
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Repl Depth: 0
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Number of connections: 13
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Current no. of conns: 0
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Current no. of operations: 0
|
The weightby feature is ignored in this case.
I think this is desired behaviour. In case of a flapping primary node and the failed over node coming back, the read_only could be enabled on both nodes. Perhaps easiest is to document it in the MMMon module? And perhaps in the weightby documentation a note that in case of multiple masters all traffic is always redirected to the last master?
Thanks,
Michaël