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#28 Bad performances when setting variables across a LAN 100 Mb

open
nobody
None
5
2004-03-15
2004-02-20
No

On a local Linux machine, it takes roughly 2 ms to to
send a command (LOCAL VAR GLOBAL SET).

Bewteen 2 Linux machines on a LAN (RTD = 0.5 ms), it
takes roughly 40 ms to send this command.

Any idea ?

Note : enclosed is .cap file

Discussion

  • sebastien vichard

    • assigned_to: nobody --> davepitcher
    • summary: Bad performances when setting variables across a network --> Bad performances when setting variables across a LAN 100 Mb
     
  • Sharon Lucas

    Sharon Lucas - 2004-03-09

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    user_id=285070

    Is there a reason why this support request was assigned to
    davepitcher? Also, I don't see a .cap file attached (though
    I'm not sure what a .cap file is).

     
  • Charles Rankin

    Charles Rankin - 2004-03-11

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    user_id=279901

    I figured I'd chime in here. This is pretty close to what I
    would expect. I have, in general, found that high-throughput
    requests are about an order of magnitude slower when going
    to a remote system. This is (largely) due to the overhead of
    establishing a tcp/ip connection for each request. In the
    future we intend to look into caching established connections
    so that we don't have this overhead for every request (much
    as HTTP 1.1 added over HTTP 1.0). This won't remove all the
    disparity between local and remote requests, but it should
    bring it down from an order of magnitude to something closer
    to a small factor.

    I just did a few tests and I'm actually getting substantially
    worse performance than you. I'm in the area of 2-3 orders of
    magnitude, depending on just how many routers/switches I'm
    going through.

    We'll look and see if there is any short term fix we can put in
    place. Otherwise, we'll have to wait until we can test out the
    connection caching idea.

     
  • sebastien vichard

    • assigned_to: davepitcher --> nobody
     
  • sebastien vichard

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    user_id=764552

    Please find enclosed the .cap file (IP traffic monitored w/
    Ethereal/TCPDump).

     
  • sebastien vichard

     

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