This patch series adds load-balancing of UDP SIP based on Call-ID to IPVS as well as a frame-work for extending IPVS to handle alternate persistence requirements. OVERVIEW The approach that I have taken is what I call persistence engines. The basic idea being that you can provide a module to LVS that alters the way that it handles connection templates, which are at the core of persistence. In particular, an additional key can be added, and any of the normal IP address, port and protocol information can either be used or ignored. In the case of the SIP persistence engine, the only persistence engine, all the keys used by the default persistence behaviour are used and the callid is added as an extra key. I originally intended to ignore the cip, but this can optionally be done by setting the persistence mask (-M) to 0.0.0.0 while allowing the flexibility of other mask values. It is envisaged that the SIP persistence engine will be used in conjunction with one-packet scheduling. I'm interested to hear if that doesn't fit your needs. CONFIGURATION A persistence engine is associated with a virtual service (as are schedulers). I have added the --pe option to the ivpsadm -A and -E commands to allow the persistence engine of a virtual service to be added, changed, or deleted. e.g. ipvsadm -A -u 10.4.3.192:5060 -p 60 -M 0.0.0.0 -o --pe sip There are no other configuration parameters at this time. RUNNING When a connection template is created, if its virtual service has a persistence engine, then the persistence engine can add an extra key to the connection template. For the SIP module this is the callid. More generically, it is known as "pe data". And both the name of the persistence engine, "pe name", and "pe data" can be viewed in /proc/net/ip_vs_conn and by passing the --persistent-conn option to ipvsadm -Lc. e.g. # ipvsadm -Lcn --persistent-conn UDP 00:38 UDP 10.4.3.0:0 10.4.3.192:5060 127.0.0.1:5060 sip 193373839 Here we see a single persistence template (cport is 0), which has been handled by the sip persistence engine. The pe data (callid) is 193373839. In the case where the persistence engine can't match a packet for some reason, the connection will fall back to the normal persistence handling. This seems reasonable, as that if the packet ought to be dropped, iptables could be used. A limited amount of debugging information has been added which can be enabled using a value of 9 or greater in /proc/sys/net/ipv4/vs/debug_level CODE AVAILABILITY The kernel patches (13) are available in git as the pe-0.4 branch of git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-test-2.6.git The ipvsadm patches (2) are available in git as the pe-0.4 branch of git://github.com/horms/ipvsadm-test.git I will post the ipvsadm patches separately -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
