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https://issues.apache.org/jira/browse/OOZIE-1561?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13784482#comment-13784482
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Robert Kanter commented on OOZIE-1561:
--------------------------------------

Alternatively, instead of pinging to determine up status, we can have a 
background thread doing a heartbeat that would update a timestamp in the ZK 
info for that server; other servers could assume that a server is down if it's 
timestamp is "too old".  

> When using Oozie HA, the logs should also be HA
> -----------------------------------------------
>
>                 Key: OOZIE-1561
>                 URL: https://issues.apache.org/jira/browse/OOZIE-1561
>             Project: Oozie
>          Issue Type: Improvement
>          Components: HA
>    Affects Versions: trunk
>            Reporter: Robert Kanter
>            Assignee: Robert Kanter
>            Priority: Critical
>
> Currently, if an Oozie server goes down, the logs from that server become 
> unavailable until the server comes back up.  In the meantime, the user may or 
> may not be aware that log messages could be missing when Oozie streams logs 
> to the user.  
> We should come up with a way to make the logs HA.  
> Some ideas:
> # When rolling the logs, copy them into HDFS; Oozie servers can then read the 
> log files directly from HDFS instead of each other
> #- The downside to this is that there will be a window where logs could still 
> be missing as they only show up in HDFS after rolling over (default = 1hr) 
> and Oozie servers would still have to contact each other for the last hour of 
> logs
> #- The upside is that it minimizes the amount of logs that could be missing 
> and would be fairly straightforward to implement
> # Log directly to HDFS
> #- The downside is that this may be complicated or tricky to get working 
> properly
> #-- This also introduces a strict dependency on HDFS
> #- The upside is that this would completely solve the issue and Oozie servers 
> would simply get all logs directly from HDFS
> # Log to ZooKeeper or a database
> #- I think the log files will be too big to do this
> I've assigned this to myself, but if someone wants to tackle this, feel free 
> to reassign it.  I think idea 2 is the most practical, but I'm also open to 
> other ideas on how to do this.  



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