The example configurations above, if started as root, will increase the file descriptor limits for the schedd and the collector. +{section: Increase kernel firewall connection tracking table size} + +For collectors with a very large number of connections running on Linux machine +with a kernel firewall, the size of the connection tracking table in the firewall may become a bottleneck. On many systems, there is a limit of 64k connections. This can be raised by setting a new limit in + +{code} +/proc/sys/net/netfilter/nf_conntrack_max +{endcode} + + {section: Turn Off Match Notification} In HTCondor's default configuration, the negotiator notifies a startd when a job matches it. This can slow job dispatch for the entire pool if the startd has vanished but HTCondor hasn't noticed yet, because the notification has a blocking a time out. For pools using spot instances (which may frequently vanish without warning), we recommend turning off match notification.