16 January 2005

PubSub lagtime data: If you need it fast, use the PubSub box; if you have a day or two use the XML feed

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Jeremy Zawodny muses:
It'd be interesting to simply measure the lag time in the index updates (freshness) for each service. I'd probably use PubSub as a baseline to do that. PubSub is fresh and comprehensive, but it doesn't keep any history. It provides notification or alerts based on pre-defined queries, not ad-hoc queries that look back in time.

Mud's Tests:

PubSub has two primary search-systems: One is the bookmark in the "My Subscription Stack", the second is the XML-feed-URI/URL.

  • Hits with PubSub's "My Subscription Stack" has 15-18 min lag to report the first hit; while

  • XML feed subscription-URI can take 24 hours or more to generate 1 hit in the subscription.

  • Appears PubSub does not necessarily process the XML-feeds in sequential order received, confounding time estimates to "when the subscription is ready" to deliver a hit.

    Note that PubSub's modified date in the subscription changes to the current time each time you ping it, even if there's no content. After the first hit in the subscription the "modified date" changes with each hit in the subscription.

    Detailed data available.

    Ref Ref Ref Ref Ref

    Jeremy Zawodny muses:
    It'd be interesting to simply measure the lag time in the index updates (freshness) for each service. I'd probably use PubSub as a baseline to do that. PubSub is fresh and comprehensive, but it doesn't keep any history. It provides notification or alerts based on pre-defined queries, not ad-hoc queries that look back in time.

    Mud's Tests:

    PubSub has two primary search-systems: One is the bookmark in the "My Subscription Stack", the second is the XML-feed-URI/URL.

  • Hits with PubSub's "My Subscription Stack" has 15-18 min lag to report the first hit; while

  • XML feed subscription-URI can take 24 hours or more to generate 1 hit in the subscription.

  • Appears PubSub does not necessarily process the XML-feeds in sequential order received, confounding time estimates to "when the subscription is ready" to deliver a hit.

    Note that PubSub's modified date in the subscription changes to the current time each time you ping it, even if there's no content. After the first hit in the subscription the "modified date" changes with each hit in the subscription.

    Detailed data available.

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