[
https://issues.apache.org/jira/browse/OOZIE-1561?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13784321#comment-13784321
]
Alejandro Abdelnur commented on OOZIE-1561:
-------------------------------------------
I was thinking that we should remember in ZK all the oozie instances that came
up (remember always). then the log streaming will report the missing instance
when that list does not match the current instances. and an admin command would
allow an admin to purge an instance that is gone forever.
If we want to go the HDFS logging, then we should create an HDFSLogAppender and
ensure it does hflush() on every message. Also, it should be async on the
writing side (Oozie server) to not slowdown Oozie processing. Though the later
means some logs could be lost in the case of an Oozie instance crashing.
> 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.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
