Re: [Bug 1359975] pmchart run-away mem leak replaying multi-archive when rewinding
"Ken McDonell" <[email protected]>
| Newsgroups | gmane.comp.sysutils.pcp |
|---|---|
| Message-ID | <[email protected]> |
On 16/12/16 10:33, Nathan Scott wrote: > Hi Dave, > > ----- Original Message ----- >> [...] >> *ordered.patch.txt*: Uses memcmp within sameindom() to compare the >> instances, assuming that the instances within instance domains will >> always be ordered in the same way. >> >> *unordered.patch.txt*: Alternate implementation of sameindom() to be >> used if we can not assume that the instances within instance domains >> will always be ordered in the same way. > > I came across the metric "sample.scramble.bin" today, which should be > able to provide a definitive test case here such that the above (open > question re sorting) can be answered... Re the "open" question ... in my mind, and instance domain is a (mathematical) set, so there is no assumed order. Indeed, PMAPI clients that really care when an instance domain changes typically check instances returned from pmFetch by either doing the (potentially n^2) exhaustive search (like pmlogger) or sorting the pmValueSet on internal instance id (like pmie). I'd expect well-behaved PMAPI clients to do the same ... because instance domains are dynamic, you cannot assume that if instance J is returned as the Kth value in a pmResult for one pmFetch that instance J will be the Kth value in a subsequent pmResult. I think there are some clients that have a fast path check that the Kth value is for instance J (as it is often the case that the positions in pmResults are long-term stable), but then fall back to a full search if the fast path check fails (but do not assume the instances to be ordered for the full search). -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#14911): https://groups.io/g/pcp/message/14911 View All Messages In Topic (5): https://groups.io/g/pcp/topic/3803079 Mute This Topic: https://groups.io/mt/3803079?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 -=-=- pcp mailing list [email protected] https://groups.io/g/pcp/messages -=-=-=-=-=-=-=-=-=-=-=-