Keepalived - New pre-release version available

I have today pushed a major update to keepalived that adds a large
amount of new functionality, efficiency improvements, and speeding up
of actions after events occur (e.g. transition to master from backup,
state changes after track_script execution). The new code is available
in the beta branch at https://github.com/acassen/keepalived/tree/beta ,
and below is a list of the main changes from the master branch.

It is intended that this branch will form the basis of the next major
 release of keepalived, and it is very much hoped that as many people
as
 possible will be able to test this new code prior to its full release.
If you have successfully tested/tried the new code, any reports of what
you have done and how it worked would be very useful. Issue #686 at htt
ps://github.com/acassen/keepalived/issues/686 has been created for this
purpose.
If you find any issues with the new code, please report them using the
Issues feature on 
github at https://github.com/acassen/keepalived/issues id="-x-evo-
selection-start-marker">. Please clearly indicate that the issue was
found with the beta 
branch code (add the beta label to the issue), include the output of
keepalived -v, a copy of
 your configuration, what Linux distrubution you are running on, and 
whether you are running keepalived in a VM or container, with details
of
 those as appropriate.
Have fun with it, and many thanks in advance for any test reports.
Quentin Armitage
The following enhancements are included in this branch.   1. 
Transition to master as soon as decision is made to do so, rather 
than wait one further advert interval.  This meant that previously if
a 
master went down and sent a priority 0 message, there was one extra 
advert interval before the highest priority backup configured the VIP 
addresses.  This means that if vrrp instances have high priorities
(i.e.
 close to 255), then the transition to master and configuration of 
addresses will now occur in a small multiple of advert_interval/256.

   2. 
Process interface state changes immediately rather than waiting for 
timer expiry. The problem was that if an interface went down and came 
back up before the next timer expiry, and addresses, routes and VMACs 
that we had configured on that interface would be removed, but we 
would't know about it.

   3. 
Add support for hot-swappable NICs, i.e. handle interfaces being
deleted and restored.

   4. 
Add vrrp_track_file option. This allows track_scripts, which are run 
on a frequent scheduled basis, to be replaced with a vrrp_track_file, 
which contains a number as a text string which is used in the same way 
as the exit status from a track script.  The track_files are only read 
if they are changed, so external events can update a track file,
rather 
than their status needing to be detected by polling by track scripts.

   5. 
Add notify fifos. Rather than sending notifications via notify 
scripts it is now possible to send notify messages via fifos. Not only 
does this mean that the overhead of executing  script for each 
notification is removed, but it also guarantees the delivery of 
notifications in the correct order, whereas if the notification is via 
scripts, there is no guarantee that the scripts will execute in the 
desired order if two or more notifications are sent in quick
succession.
  There can be a global fifo to process all notifies, and also
separate 
fifos for vrrp and checkers.  It is possible to specify a script for 
keepalived to execute to process the messages on the fifo(s).

   6. 
Stop logging address addition/deletions if they are not relevant to
keepalived (unless the -a option is specified).

   7. 
Transition to fault state if source address for adverts is deleted from
interface

   8. 
Transition to backup state if a VIP or eVIP is removed. When we next 
transition to master the addresses will be restored. If nopreempt is
not
 set, that will be almost immediately.

   9. 
Make an address owner (priority 255) transition to master immediately

  10. 
Don't process a received advert if the authentication fails.

  11. 
Ignore invalid received adverts totally (the master down timer was 
being updated, which meant that a backup could be stuck in backup
state 
even if the only received adverts were invalid).

  12. 
Don't reset timer before sending next advert if receive a lower
priority advert.

  13. 
Log if receive invalid authentication header

  14. 
Ignore lower priority adverts when backup (to comply with RFCs) this 
also means that the master down timer isn't reset, which was causing a 
delay to becoming master

  15. 
Fix first advert interval of vrrp instances in a sync group.

  16. 
Stop two vrrp instances with preempt delay and equal priorities flip-
flopping between master and backup state

  17. 
Make sync group members transition state at same time as first 
instance makes transition (i.e. when the trigger event occurs) rather 
than wait for next timer expiry

  18. 
If a vrrp track script returns a new status code, process that 
immediately for all instances (and their sync group members) rather
than
 waiting for the next timer expiry on each instance.

  19. 
On reload, make track scripts inherit the last state from before the 
reload.  This stops vrrp instances transitioning to down and coming
back
 up once the script has run.

  20. 
Correct the use of adver_int and master_adver_int

  21. 
Ensure when leaving fault state that a vrrp instance transitions to
backup unless it has priority 255

  22. 
Remove quick_sync functionality since no longer needed.

  23. 
Improved code efficiency:
a.  Finding vrrp instance after read timeout
b.  When getting interface information for a new vmac, only request
information for that i/f.
c.  Directly update effective priority of vrrp instances when scripts
return new status rather than scheduling a thread to do it
d.  Don't run a read timeout on vrrp instance in fault state
e.  Don't run a track script if no vrrp instance is tracking it
f.  Stop checking interface status after every timer expiry since
processing interface state changes is now done synchronously
g.  The timeout for the select call had a maximum timeout of 1 second,
it now times out only when something needs to happen
h.  The timeout on netlink reads was 500 seconds and this has been
extended to 1 day.
i.  Streamline signal handling between main process and child process
by using signalfd if available, rather than using a pipe
j.  Minimise searching for an interface struct based on its index by
using pointers to the interface structures
k.  Stop opening and closing vrrp scripts before running them. We can
detect they are missing from the return of the exec call.
l.   Allow threads that don't need a timeout to never timeout
m. Calculate the maximum fd number when calling select() rather than
specifying the maximum of 1024.
m.  Ignore netlink NEWLINK messages that are only wireless state
changes.
o.  Don't check whether timers have expired after select() returns if
its timeout didn't expire.
p.  Termination of child processes (scripts) were being handled twice
q.  Don't generate the IP header checksum since the kernel will always
generate it.
r.  Maintain pointers to tracking scripts to save seaching a list to
find the relevant script.
s.  Vrrp instances to have pointer to interface structure to avoid
having to search based in index

  24. 
Fix the checksum calculation for VRRPv3 unicast peers.

  25. 
Don't regenerate the full vrrp_advert packet data each time an advert
 is sent; simply update the necessary fields and calculate the change 
needed to the checksum.

  26. 
Detect a vmac interface going down, and make the vrrp instance 
transition to fault state. Previously the instance would only go down
if
 the underlying interface went down.

  27. 
Stop weighted track scripts updating priority of sync group members

  28. 
Make vrrp instances go straight to fault state at startup if a 
relevant interface is down, rather than start in up state and
transition
 to fault at next timer expiry

  29. 
Ensure that a sync group starts in backup state unless all members are
address owners

  30. 
Restore master down timer after leaving fault state

  31. 
Use execve() to execute scripts rather than system(). This saves a 
fork and an extra process, and also allows the parameters to be parsed 
once only at startup, rather than each time the script is invoked.

  32. 
Don't treat a failure to execute a script as a failure of the script.

  33. 
Ensure all scripts receive TERM signal when keepalived terminates

  34. 
If keepalived is running with an elevated priority, stop running
scripts with that elevated priority.

  35. 
Enable an unweighted tracking script make a vrrp instance which is an
address owner transition to fault state

  36. 
Delay bringing vrrp instances up at startup until after the first 
completion of the tracking scripts to stop an instance coming up an
then
 being brought back down again after the script completes with a 
failure.

  37. 
Reduce number of error messages if a script is not executable

  38. 
Add linkbeat option per vrrp instance

  39. 
Fix timer addition on 32-bit systems

  40. 
Ignore netlink messages for interfaces using linkbeat polling

  41. 
If priority of vrrp instance changes when in backup due to a vrrp
script, reschedule the read timeout

  42. 
If re-using a VMAC after a reload, ensure it is correctly configured

  43. 
Don't send priority 0 adverts when transition to fault state unless
were in master mode

  44. 
Identify routes added by keepalived as belonging to keepalived

  45. 
Enable vrrp instances to be put into fault state if their routes are
removed

  46. 
Add track scripts and track files and track_if to sync groups and 
deprecate global_tracking (use sync_group_tracking_weight instead, but 
only if necessary).

  47. 
Improve AH authentication sequence number handling, and (re)enable
sequence number checking for VMACs and sync groups


The things remaining to do include:


   1. 
Addresses being removed (static and vips)
tracking static addresses

   2. 
Routes/rules being removed (static and dynamic)
route can be removed if i/f goes down
tracking static rules/routes

   3. 
Allow specification for interfaces on existing at startup - but report
them.
When interface later created, bring up any vrrp instances and routes
that should be using it.

   4. 
May need to restore static routes/addresses when interfaces are
restored

   5. 
Add track_if/track_route for static routes

   6. 
Add option for whether vrrp instance to go down if static/dynamic
rule/route/address disappears

   7. 
Add static addresses and routes on vmacs

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