Messages in this thread | | | Date | Thu, 29 Aug 2013 10:57:09 +0900 | From | Yoshihiro YUNOMAE <> | Subject | Re: Re: [RFC PATCH 08/11] trace-cmd: Apply the trace-msg protocol for communication between a server and clients |
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(2013/08/28 23:42), Steven Rostedt wrote: > On Wed, 28 Aug 2013 20:30:17 +0900 > Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> wrote: > >> (2013/08/27 22:05), Steven Rostedt wrote: >>> On Tue, 27 Aug 2013 19:23:24 +0900 >>> Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> wrote: >>> >>>> OK, let me check that. Even if the old server will receive "V2", the >>>> server will send port numbers instead of "V2" due to the old protocol. >>>> In that time, the new client will disconnect from the old server and >>>> the restarts with the old protocol. Is it OK? >>> >>> Yep, that's exactly what I meant ;-) >> >> I tried to implement the feature, but I found that sending just "V2" >> from the new client is inappropriate. This is because the old server >> doesn't respond to the client before receiving cpu numbers, page size, >> and options. So, when the new client sends the first message, it should >> send "V2\0<MAGIC_NUMBER>\00\0", I think. If so, the old server will >> understand the message as cpus=0, pagesize=<MAGIC_NUMBER>, options=0, >> and then it will send port numbers(actually \0). Note if <MAGIC_NUMBER> >> is zero, the old server will die. >> >> Can I implement the first message of the new client as >> "V2\0<MAGIC_NUMBER>\00\0"? >> > > If it works for both old and new server with old and new client (and > all combinations) I'm fine with it.
OK, I'll submit trace-cmd patches as V2 in a few days.
Thanks, Yoshihiro YUNOMAE
-- Yoshihiro YUNOMAE Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: yoshihiro.yunomae.ez@hitachi.com
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