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787N/A<H1 ALIGN="CENTER">Server Pool Management</H1>
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294N/A<P>
294N/AWe found that many people were using values for "MaxServers" either
294N/Atoo high or too low, and were hanging themselves on it. The model we
294N/Aadopted is still based on long-lived minimal-forking processes, but
294N/Ainstead of specifying one number of persistent processes, the
294N/Aweb-master specifies a maximum and minimum number of processes to be
294N/A"spare" - every couple of seconds the parent checks the actual number
787N/Aof spare servers and adjusts accordingly. This should keep the number
787N/Aof servers concurrently running relatively low while still ensuring
787N/Aminimal forking.
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294N/A<P>
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294N/AWe renamed the current StartServers to MinSpareServers, created
294N/Aseparate StartServers parameter which means what it says, and renamed
294N/AMaxServers to MaxSpareServers (though the old name still works, for
294N/ANCSA 1.4 back-compatibility). The old names were generally regarded
294N/Aas too confusing.
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787N/A<P>
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294N/AThe defaults for each variable are:
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294N/A<PRE>
787N/AMinSpareServers 5
294N/AMaxSpareServers 10
294N/AStartServers 5
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294N/A
294N/AThere is an absolute maximum number of simultaneous children defined
294N/Aby a compile-time limit which defaults to 256 and a "MaxClients"
294N/Adirective which specifies the number of simultaneous children that
294N/Awill be allowed. MaxClients can be adjusted up to the compile-time
294N/Alimit (HARD_SERVER_LIMIT, defined in httpd.h). If you need more
787N/Athan 256 simultaneous children, you need to modify both HARD_SERVER_LIMIT
787N/Aand MaxClients.<P>
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294N/AIn versions before 1.2, HARD_SERVER_LIMIT defaulted to 150.<P>
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294N/AWe do not recommend changing either of these values unless:
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787N/A<OL>
787N/A<LI>You know you have the server resources to handle more
294N/A<LI>You use the machine for other purposes and must limit the amount of memory
787N/AApache uses
294N/A</OL>
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