Re: pmlogrewrite quirk/bug?

"Ken McDonell" <[email protected]>
Newsgroups gmane.comp.sysutils.pcp
Message-ID <[email protected]>
On 25/10/16 08:46, Ken McDonell wrote:
> ...
> I spoke too soon ... qa/827 is passing, but a bunch of other -g
> pmlogrewrite tests are now failing ... I'll need to spend more time
> understanding what's going on here before pushing any code changes.

OK, now I think I understand.

pmlogrewrite is actually correct and pmlogger is not quite correct and 
pmlogextract follows the pmlogger approach.  The problem is the 
"preamble" pmResult that contains pmcd.pmlogger.host, pmcd.pmlogger.port 
and pmcd.pmlogger.archive and more importantly these are defined over 
the instance domain 2.1.

For pmlogger, the preamble is written first, then all of the remaining 
pmResult records are written from the callback method ... and the 
temporal index is only updated in the callback method, which means the 
instance domain from the preamble does not trigger a temporal index write.

For pmlogrewrite the preamble record is treated the same as any other 
pmResult and the temporal index write logic applies.

The difference is is purely academic given that the only metadata 
between the offset 351 and 7893 in the meta data files are pmDesc 
records for the first real pmResult.  If you're scanning for an instance 
domain (the only time the metadata offsets in the temporal index is 
used) it makes no difference if you start at 132 or 7983, and indeed 
since the _last_ pmResult containing an instance domain is the preamble 
at 10:10:27.854 (the timestamp on the first temporal index entry) then 
the last temporal index entry will never be used when scanning for an 
instance domain.

So I think it is a "quirk" and I'll adjust the 827.out if you agree.

I probably should write down how this archive stuff really works, 
sometime before I die.


-=-=-=-=-=-=-=-=-=-=-=-
pcp mailing list
[email protected]
https://groups.io/g/pcp/messages
-=-=-
Groups.io Links:

You receive all messages sent to this group.

View/Reply Online (#14602): https://groups.io/g/pcp/message/14602
View All Messages In Topic (4): https://groups.io/g/pcp/topic/2968875
Mute This Topic: https://groups.io/mt/2968875?uid=174580
New Topic: https://groups.io/g/pcp/post

Change Your Subscription: https://groups.io/g/pcp/editsub?uid=174580

Group Home: https://groups.io/g/pcp
Contact Group Owner: [email protected]

Terms of Service: https://groups.io/static/tos

Unsubscribe: https://groups.io/g/pcp/leave/354243/563757577/xyzzy
-=-=-=-=-=-=-=-=-=-=-=-
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.