Re: performance of jailed processes

From: Robert Watson (rwatson_at_freebsd.org)
Date: 03/30/04

  • Next message: Dag-Erling Smørgrav: "Re: performance of jailed processes" 
    Date: Tue, 30 Mar 2004 16:00:03 -0500 (EST)
To: Dag-Erling Smørgrav <des@des.no>

    On Tue, 30 Mar 2004, Dag-Erling Smørgrav wrote:

    > Robert Watson <rwatson@freebsd.org> writes:
    > > Somewhat more painful suggestion, but could you generate ktraces against a
    > > mysql client doing the query inside and out of jail, then using whatever
    > > flag sets relative timestamps on kdump, diff the two and see where the
    > > substantial differences begin?
    >
    > I'll give it a shot tomorrow.

    I've had quite a bit of luck resolving mysql problems in jail using this
    approach, fwiw, during some confusion relating to UNIX domain sockets at
    an ISP I provide some help to.

    > > 13 seconds is too long for most of the potential things I have in mind...
    >
    > although the query only returns one row, it's a pretty big row, so 13
    > seconds could be explained by per-syscall or per-packet overhead.

    Theory goes that there should be no per-read/write system call change in
    behavior for TCP with jail. Jail impacts bind/connect, and potentially
    each I/O on UDP for an unbound socket using sendto.

    Robert N M Watson FreeBSD Core Team, TrustedBSD Projects
    robert@fledge.watson.org Senior Research Scientist, McAfee Research

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  • Next message: Dag-Erling Smørgrav: "Re: performance of jailed processes"

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