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https://issues.apache.org/jira/browse/GEODE-8687?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jakov Varenina reassigned GEODE-8687:
-------------------------------------

    Assignee: Jakov Varenina

> Durable client is continuously re-registering CQs on all servers when event 
> de-serialization fails causing resource exhaustion on servers 
> ------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: GEODE-8687
>                 URL: https://issues.apache.org/jira/browse/GEODE-8687
>             Project: Geode
>          Issue Type: Bug
>          Components: client/server
>    Affects Versions: 1.13.0
>            Reporter: Jakov Varenina
>            Assignee: Jakov Varenina
>            Priority: Major
>         Attachments: deserialzationFault.log
>
>
> When ReflectionBasedAutoSerializer is wrongly/not set it results with 
> serialization exception on client at the reception of the CQ events. 
> Serialization exception isn't logged which is misleading, and is hard to find 
> that actually ReflectionBasedAutoSerializer isn't set correctly. Only log 
> that can be seen is that client/servers subscription connections are closed 
> due to EOF. This is because client destroys subscriptions connections 
> intentionally, but doesn't log reason (PdxSerializationException) that led to 
> this. It would be good that serialization exceptions are logged as error or 
> warn.
> Client destroys subscription connection and perform server fail-over whenever 
> serialization issue occurs. Additionally when subscription connection for 
> particular server fails multiple times then this server is put in deny list 
> for 10 seconds (this is configurable with {{ping-interval}}). After 10s 
> expire the server is removed from list and it is available for subscription 
> connection which will be destroyed again due serialization issue. This will 
> go indefinitely and approx. every 10s in this case the client subscribes to 
> each servers at least once. Due to serialization issue events aren't sent to 
> client and remain in subscription queues.
> Whenever connection fails due to serialization issue and client is not 
> durable then subscription queue is closed and events are lost.
> The biggest problem arises when client is durable. This is because 
> subscription queue remains on server for configurable period of time (e.g. 
> 300s) waiting for client to reconnect. When client perform fail-over to 
> another server it will create new subscription queue using initial image from 
> old queue that is currently paused. This means that all events from old queue 
> will be transferred to new subscription queue hosted by the current primary 
> server. This will happen on all servers and all of them will have copy of the 
> queue even subscription redundancy isn't configured. The problem here is that 
> client will periodically (every 10s in this case) establish connection to 
> each servers, so configured timeout (e.g. 300s) will never expire, but it 
> will be renewed each time client is registered. This could cause a lots of 
> problems since memory and disk usage (if overflow on queue is configured) 
> will increase on all servers.
> You can find in attached logs for the problematic case with durable client :
> vm0              -> locator
> vm1, vm2   -> servers
> vm3              -> durable client with enabled subscription handling CQ 
> events
> vm4              -> client generating traffic that should trigger registered 
> CQ
>  



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