[
https://issues.apache.org/jira/browse/FLUME-3149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16152277#comment-16152277
]
Bessenyei Balázs Donát commented on FLUME-3149:
-----------------------------------------------
Hi [~zyfo2],
Regarding the persisted flag, that would be basically for "polling" if the
callback implementation was overly complicated. Ie. on pushing new events to
the channel, source would check if everything has been committed from the
previous batch. Probably not the nicest implementation, but an "easy" one. For
the callback approach, you have got it right, that's what I've meant.
The "persisted" flag would mean the event is "safely" committed, ie. somewhere
on disk, etc. More like "committed".
Thank you,
Donat
> reduce cpu cost for file source transfer while still maintaining reliability
> ----------------------------------------------------------------------------
>
> Key: FLUME-3149
> URL: https://issues.apache.org/jira/browse/FLUME-3149
> Project: Flume
> Issue Type: Improvement
> Components: File Channel
> Reporter: Will Zhang
>
> File channel tracks transferred events and use transnational mechanism to
> make transfer recoverable. However, it increases CPU cost due to frequent
> system calls like write, read, etc. The Cpu cost could be very high if the
> transfer rate is high. In contrast, Memory channel has no such issue which
> requires only about 10% of CPU cost in the same environment but it's not
> recovered if the system is down accidentally.
> For sources like taildir/spooldir, I propose we could track offsets of file
> and store them locally to achieve reliability while still using memory
> channel to reduce CPU cost. Actually, I have already implemented this feature
> by storing the offsets in event headers and passing it to my own
> "offsetMemoryChannel" and store theses offsets in local disk in our
> production which reduces CPU cost by about 90 percent.
> Please let me know if it's worthwhile to have this feature in community
> version. Thank you.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
