[Keepalived] Release 0.4.8

["Alexandre CASSEN" <alexandre.cassen@xxxxxxxxxxxxxx>]

Hi all,

I have just submit the new keepalived release 0.4.8. The main enhancement
is the VRRPv2 implementation with synchronization instance.

download link :
http://keepalived.sourceforge.net/software/keepalived-0.4.8.tar.gz

I have produce the following paper to explain the keepalived internals
implementation :
http://keepalived.sourceforge.net/pdf/LVS-HA-using-VRRPv2.pdf

I will update the QuickStart guide to refresh it with the configuration
presented into the VRRP paper.

The ChangeLog for the release is :


2001-11-20  Alexandre Cassen  <acassen@xxxxxxxxxxxx>
        * keepalived-0.4.8 released.
        * Rewrite the whole VRRP previous code.
        * VRRP : Created a hierarchic scheduling framework.
          Handle VRRP instances multiplexing on the same I/O fd.
          VRRP I/O events are handled by our global scheduling
          framework. Then the global sheduling framework call a VRRP
          I/O instance dispatcher to manage VRRP instances.
        * VRRP : Created a temporary socket pool to handle register
                 our VRRP thread instances.
          We create & allocate a socket pool here. The soft design
          can be sum up by the following sketch :

                 fd1  fd2    fd3  fd4          fdi  fdi+1
              -----\__/--------\__/---........---\__/---
                 | ETH0 |    | ETH1 |          | ETHn |
                 +------+    +------+          +------+

          Here we have n physical NIC. Each NIC own a maximum of 2 fds.
          (one for VRRP the other for IPSEC_AH). All our VRRP instances
          are multiplexed through this fds. So our design can handle 2*n
          multiplexing points.
        * VRRP : Review the multicast socket creating. We bind the socket
          to a specific NIC. inbound & outbound traffic are bound to the
          NIC.
          => why IP_ADD_MEMBERSHIP & IP_MULTICAST_IF doesnt set
             sk->bound_dev_if themself ??? !!!
             Needed for filter multicasted advert per interface.
          => For inbound binding we use SO_BINDTODEVICE kernel option.
        * VRRP : Created a read dispatcher thread to deal with our
sockpool.
          Handle VRRP states & transition states.
        * VRRP : Created a VRRP synchronization instance circuit. This
          functionnality gave you the ability to monitor VRRP instance
          each other. This mean that if 2 VRRP instances are monitoring
          themself and if one of this instance change state, the other
          follow the same state. ex.: With 2 VRRP instances (VI_1 & VI_2)
          if VI_1 become backup then VI_2 become backup too. (symetricly
          with master VRRP state).
        * VRRP : Rewrite the netlink interface to use non blocking socket.
        * VRRP : Rewrite the ipaddress handling to use the new netlink
          interface.
        * VRRP : Remove the VRPP VMAC handling since linux kernel only
          permit to use one MAC address on a specific NIC. We use
gratuitous
          arp when setting up VRRP VIP, to uptade remote host arp caches.
          => In certain case this can cause a TCP session renegociation
             which can cause a permature session end.
          => To be fully compliant with the VRRP RFC, need to patch the
             kernel to gave it the possibility to deal with more than one
             MAC address at a time. Give me clue on it please ! to same me
             a little time :)
        * Starting VRRP documentation.
        * Patch a pidfile handling bug when forking the keepalived daemon.
          Thanks goes to Gianni D'Aprile for pointing it to me.
        * Patch a timer race condition into the scheduling framework.
          This bug caused tcpcheck to respawn quickly...
          Thanks goes to Gianni D'Aprile for pointing it to me.


All comments are Welcomes...

Best regards,
Alexandre