[ANNOUNCE] Keepalived 0.5.9

[Alexandre Cassen <Alexandre.Cassen@xxxxxxxxxx>]

Hi all,

I have just published the new Keepalived release. The work done on this 
release was focused on the VRRP framework, adding extension and probe the 
code on a real world production env. I would like to specially thanks Paul, 
<xerox@xxxxxxxxxx> for his time simulating heavy load on its network and 
providing me access to his pre-production Internet Backbone.
The most important issue we observed was VRRP instance state flapping. We 
simulated a heavy loaded network using juno & ping flooding to simultate 
DOS. The constatation were : "hey VRRP is constantly flapping.... !!!!! 
Whats the hell with this". The problem was not, as I previously posted, a 
packet dropping issue due to a congested network, it was, it was... yes, 
yes, it was :) => grrr a VRRP timer degradation that caused a too long 
delay sending MASTER advert.... After the issue fixed, we probe on the 
heavy loaded network (with 2 linux routers) => 80,000 pps, and no 
problems... After a 3 days work fulltime on this issue, the bug was fixed 
with one code line !!!! some time coding network engine is really 
frustrating ! :)
The ChangeLog for this new release is :

2002-05-30  Alexandre Cassen  <acassen@xxxxxxxxxxxx>
        * keepalived-0.5.9 released.
        * Added support to realserver_group. The work is not yet finished 
since
          it introduces new compilation design currently not supported. So 
please
          do not use yet.
        * VRRP : Review the script notification. Moved to a script per VRRP
          instance state => Created new keywords notify_backup|master|fault
          to run a specific script during backup|master|fault state 
transition.
        * VRRP : Added support to quoted strings for 
notify_backup|master|fault.
          Can now launch script passing arguments.
          See sample directory for examples.
        * VRRP : Added a protocol extension called 
"virtual_ipaddress_excluded".
          This configuration block is similar to "virtual_ipaddress" block =>
          those VIPs (called E-VIPs) are set throught netlink kernel 
channel and
          gratuitous arp are sent over each E-VIP. The only difference is that
          they are not added into VRRP packet adverts. This can be usefull for
          big env where you want to run many VRRP VIPs (200 for example).
          VRRP packet lenght are limited to a 20 VIPs, if you want more 
VRRP VIPs
          add them to the "virtual_ipaddress_excluded" configuration block.
        * VRRP : Added more logging facility when setting/removings VIPs & 
E-VIPs.
        * VRRP : Created a new FSM state called become_master in charge of
          VIPs/E-VIPs/notifications handling. The goto_master state is now 
a state
          where the instance send an advert to force a new MASTER election 
setting
          the instance into a transition mode. If election success its finaly
          transit to become_master state to own VIPs/E-VIPs and launch 
scripts.
        * VRRP : Force a new MASTER election when receiving a lower prio 
advert.
        * VRRP : Review the vrrp_scheduler.c to use more conventional FSM 
design.
          This reduce and beautifull the code.
        * VRRP : Fixed a very noisy flapping issue observed on heavy 
loaded env.
          Simulating big traffic on a backbone figure out this flapping issue.
          Added support to a TIMER_MICRO_ADJUST to prevent against timer 
degradation.
          This can be view as a DOS protection policy. VRRP MASTER timers 
are adjusted
          if they are too degradated, due to heavy loaded networking env 
introducing
          latency receiving/sending VRRP protocol adverts.
          Thanks goes to Paul, <xerox@xxxxxxxxxx> for pointing it out and 
providing
          access to its Internet routing backbone.

Any comments will be welcome,

Best regards,
Alexandre