pcp
[Top] [All Lists]

Re: PCP Multi-Archive Contexts: Treatment of Archive Boundaries

To: Ken McDonell <kenj@xxxxxxxxxxxxxxxx>
Subject: Re: PCP Multi-Archive Contexts: Treatment of Archive Boundaries
From: Dave Brolley <brolley@xxxxxxxxxx>
Date: Mon, 30 Nov 2015 15:15:39 -0500
Cc: PCP Mailing List <pcp@xxxxxxxxxxx>
Delivered-to: pcp@xxxxxxxxxxx
In-reply-to: <564CD23C.6040408@xxxxxxxxxxxxxxxx>
References: <564CCA0A.4030006@xxxxxxxxxx> <564CD23C.6040408@xxxxxxxxxxxxxxxx>
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0
Thanks for clarifying Ken.

On 11/18/2015 02:32 PM, Ken McDonell wrote:

See the pmlogextract code to see how to generate an appropriate timestamp for the <mark> record.

I have a couple of observations and questions:
  1. It looks like the timestamp for the <mark> record is 1 millisecond after that of the previous record in the stream. I know that this is extremely unlikely, but I suppose that it's possible that, in a multi-archive context, the next archive begins less than 1 millisecond after the previous one ends. Should we worry about that and perhaps interpolate the tmestamp of the <mark> record in that case? It also seems possible that within pmLogExtract, the next record might occur less than a millisecond after the previous one. Is this a problem?

  2. From what I can tell, it looks to me like pmLogExtract could generate more than one l<mark> record in the same gap. This would be the (unlikely?) case where more than one archive ends at almost the same time and all end within the gap between the previous record and the next one. Now since we're not planning on allowing overlapping archives for multi-archive contexts, this will never happen there. I'm just interested in whether I'm understanding pmLogExtract correctly and whether this was known and/or intended.

Thanks,
Dave
<Prev in Thread] Current Thread [Next in Thread>