prefork and IPv6
morgan at orst.edu
Thu Jun 9 12:44:37 EDT 2016
On Thu, 9 Jun 2016, Wolfgang Breyha via Info-cyrus wrote:
> I recently wondered why some of my preforked processes on my murder backends
> never get used. I detected them because some quite old lmtpd's were holding
> locks on an already deleted deliver.db.
> After some debugging I recognized that cyrus-master seems to fork the
> configured amount of "prefork" daemons twice. One half listening on IPv4 and
> the other half on IPv6. Since IPv6 is practically never used from our
> frontends they stay forever doing nothing on the backends.
> Is there some reasonable way to prevent this other than setting prefork=0?
> I'm only using SERVICE entries like:
> Bimap cmd="imapd" listen="imap" prefork=5
> Only the port is used for listen= without interface/IP.
Use the proto argument:
The protocol used for this service (tcp, tcp4, tcp6, udp, udp4, udp6). This
string argument is optional.
tcp4, udp4: These arguments are used to bind the service to IPv4 only.
tcp6, udp6: These arguments are used to bind the service to IPv6 only, if the
operating system supports this.
tcp, udp: These arguments are used to bind to both IPv4 and IPv6 if possible.
Here is my cyrus.conf entry:
imap cmd="/usr/local/cyrus/bin/imapd" listen="imap" proto="tcp4" prefork=10 maxchild=4000
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