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Flume, mail # user - Preventing Data Loss during Restart


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Re: Preventing Data Loss during Restart
Friso van Vollenhoven 2013-02-13, 08:56
The link I sent in my previous message was not the correct one. Check http://www.rsyslog.com/doc/relp.html for the RELP reliable syslog protocol that rsyslog has support for. I am currently trying to figure out how stable it is and who uses it in production.

Friso
On 13 feb. 2013, at 07:47, Friso van Vollenhoven wrote:

If you are using rsyslog as your syslog daemon (the default in CentOS and RHEL), then there is such a thing as reliable TCP transport built in (http://www.rsyslog.com/doc/rsyslog_reliable_forwarding.html). Flume doesn't have a source for this, but it would be a nice feature to build it. I thought about this before. We also use syslog for sending logs to Flume and are also not keen on running Java front-end boxes, so we have the same problem.

I will try to have a look at their protocol today, to see how complex it would be (not making any promises).
Cheers,
Friso

On 12 feb. 2013, at 21:19, <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>>
 <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>> wrote:

Yeah I’m starting to answer my own question. We’re using 1.3 so we do have Avro. We were trying to avoid installing anything on our client (Source) machines so that we could avoid installing Java on machines we didn’t need it on.

From: Hari Shreedharan [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, February 12, 2013 2:42 PM
To: [EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>
Subject: Re: Preventing Data Loss during Restart

Hi,

What version of Flume are you using? Also note that Syslog is a fire and forget protocol, so when you reconfigure, any events not persisted to the file channel would be lost. Since there is no way of informing the data source that the data was not written to disk, this data could in fact be lost. We recommend using a source which actually does report failure, like Avro/Thrift (available on trunk, not in any release yet) or HTTP. This will allow you to retry if Flume reports failure.
Hari

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Hari Shreedharan
On Tuesday, February 12, 2013 at 11:24 AM, [EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]> wrote:

I’ve seen some threads on this online in the past but I can’t seem to find a distinct answer. We’re deploying Flume in a production environment where we’re going to be grabbing log data from syslog and other sources. While Flume supports run time configuration changes we are still noticing data loss during testing even with a file channel. Now, this is a single channel, source, and sink set up, no redundancy. Does anyone know of a clean way to support guaranteed delivery without redundancy?

Thanks!

Matt
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