When does a session close with a "blast"?
cosimo at streppone.it
Wed Mar 31 18:20:38 CEST 2010
We're running varnish 2.0.4 on some moderately busy
servers, ~1200 req/s peak.
Today I was looking at the output of:
varnishtop -i SessionClose
which is very interesting BTW, when I noticed
that a new value was suddenly added to the list,
that looked like this, more or less:
7557.34 SessionClose timeout
901.28 SessionClose no request
753.54 SessionClose remote closed
317.48 SessionClose error
73.18 SessionClose Connection: close
60.32 SessionClose overflow
20.81 SessionClose not HTTP/1.1
0.05 SessionClose blast <--- HERE!
1) Does this distribution look "normal"?
These servers have a sess_timeout of 2s, and they are serving
a large (tens of millions) set of medium to large files.
2) What does "blast" mean for a SessionClose?
Reading the source code for 2.0.4, it would seem to me that
"blast" originates from overflowing sess_workspace.
If this is correct, would a simple increase of sess_workspace prevent
And yes, I'm assuming a blast is a bad thing. :)
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