CTDB2releaseNotes: Difference between revisions

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* Vacuuming performance has been improved.
* Vacuuming performance has been improved.


* Record locking now compares records based on their hashes to avoid scheduling multiple requests for records on the same hashchain.
* Record locking performance has been improved.


* An internal timeout for revoking read-only record relegations has been changed from hard-coded 5 seconds to the value of the ControlTimeout tunable. This makes it less likely that ctdbd will abort.
* An internal timeout for revoking read-only record relegations has been changed from hard-coded 5 seconds to the value of the ControlTimeout tunable. This makes it less likely that ctdbd will abort.

Revision as of 01:07, 1 April 2014

ctdb 2.5.3

Release Notes for ctdb 2.5.3
April 1, 2014

Changes

User-visible changes

  • New configuration variable CTDB_NATGW_STATIC_ROUTES allows NAT gateway feature to create static host/network routes instead of default routes. See the documentation. Use with care.

Important bug fixes

  • ctdbd no longer crashes when tickles are processed after reloading the nodes file.
  • "ctdb reloadips" works as expected because the DEL_PUBLIC_IP control now waits until public IP addresses are released before returning.

Important internal changes

  • Vacuuming performance has been improved.
  • Record locking now compares records based on their hashes to avoid scheduling multiple requests for records on the same hashchain.
  • An internal timeout for revoking read-only record relegations has been changed from hard-coded 5 seconds to the value of the ControlTimeout tunable. This makes it less likely that ctdbd will abort.
  • Many test improvements and additions.

ctdb 2.5.2

Release Notes for ctdb 2.5.2
February 3, 2014

Changes

User-visible changes

  • Much improved manpages from CTDB 2.5 are now installed and packaged.

Important bug fixes

  • "ctdb reloadips" now waits for replies to addip/delip controls before returning.

Important internal changes

  • The event scripts are now executed using vfork(2) and a helper binary instead of fork(2) providing a performance improvement.
  • "ctdb reloadips" will now works if some nodes are inactive. This means that public IP addresses can be reconfigured even if nodes are stopped.

ctdb 2.5.1

Release Notes for ctdb 2.5.1
November 27, 2013

Changes

Important bug fixes

  • The locking code now correctly implements a per-database active locks limit. Whole database lock requests can no longer be denied because there are too many active locks - this is particularly important for freezing databases during recovery.
  • The debug_locks.sh script locks against itself. If it is already running then subsequent invocations will exit immediately.
  • ctdb tool commands that operate on databases now work correctly when a database ID is given.
  • Various code fixes for issues found by Coverity.

Important internal changes

  • statd-callout has been updated so that statd client information is always up-to-date across the cluster. This is implemented by storing the client information in a persistent database using a new "ctdb ptrans" command.
  • The transaction code for persistent databases now retries until it is able to take the transaction lock. This makes the transation semantics compatible with Samba's implementation.
  • Locking helpers are created with vfork(2) instead of fork(2), providing a performance improvement.
  • config.guess has been updated to the latest upstream version so CTDB should build on more platforms.

ctdb 2.5

Release Notes for ctdb 2.5
October 30, 2013

Changes

User-visible changes

  • The default location of the ctdbd socket is now:
   /var/run/ctdb/ctdbd.socket
If you currently set CTDB_SOCKET in configuration then unsetting it will probably do what you want.
  • The default location of CTDB TDB databases is now:
  /var/lib/ctdb
If you only set CTDB_DBDIR (to the old default of /var/ctdb) then you probably want to move your databases to /var/lib/ctdb, drop your setting of CTDB_DBDIR and just use the default.
To maintain the database files in /var/ctdb you will need to set CTDB_DBDIR, CTDB_DBDIR_PERSISTENT and CTDB_DBDIR_STATE, since all of these have moved.
  • Use of CTDB_OPTIONS to set ctdbd command-line options is no longer supported. Please use individual configuration variables instead.
  • Obsolete tunables VacuumDefaultInterval, VacuumMinInterval and VacuumMaxInterval have been removed. Setting them had no effect but if you now try to set them in a configuration files via CTDB_SET_X=Y then CTDB will not start.
  • Much improved manual pages. Added new manpages ctdb(7), ctdbd.conf(5), ctdb-tunables(7). Still some work to do.
  • Most CTDB-specific configuration can now be set in
 /etc/ctdb/ctdbd.conf.
This avoids cluttering distribution-specific configuration files, such as /etc/sysconfig/ctdb. It also means that we can say: see ctdbd.conf(5) for more details.  :-)
  • Configuration variable NFS_SERVER_MODE is deprecated and has been replaced by CTDB_NFS_SERVER_MODE. See ctdbd.conf(5) for more details.
  • "ctdb reloadips" is much improved and should be used for reloading the public IP configuration.
This commands attempts to yield much more predictable IP allocations than using sequences of delip and addip commands. See ctdb(1) for details.
  • Ability to pass comma-separated string to ctdb(1) tool commands via the -n option is now documented and works for most commands. See ctdb(1) for details.
  • "ctdb rebalancenode" is now a debugging command and should not be used in normal operation. See ctdb(1) for details.
  • "ctdb ban 0" is now invalid.
This was documented as causing a permanent ban. However, this was not implemented and caused an "unban" instead. To avoid confusion, 0 is now an invalid ban duration. To administratively "ban" a node use "ctdb stop" instead.
  • The systemd configuration now puts the PID file in /run/ctdb (rather than /run/ctdbd) for consistency with the initscript and other uses of /var/run/ctdb.

Important bug fixes

  • Traverse regression fixed.
  • The default recovery method for persistent databases has been changed to use database sequence numbers instead of doing record-by-record recovery (using record sequence numbers). This fixes issues including registry corruption.
  • Banned nodes are no longer told to run the "ipreallocated" event during a takeover run, when in fallback mode with nodes that don't support the IPREALLOCATED control.

Important internal changes

  • Persistent transactions are now compatible with Samba and work reliably.
  • The recovery master role has been made more stable by resetting the priority time each time a node becomes inactive. This means that nodes that are active for a long time are more likely to retain the recovery master role.
  • The incomplete libctdb library has been removed.
  • Test suite now starts ctdbd with the --sloppy-start option to speed up startup. However, this should not be done in production.

ctdb 2.4

Release Notes for ctdb 2.4
August 22, 2013

Changes

User-visible changes

  • A missing network interface now causes monitoring to fail and the node to become unhealthy.
  • Changed ctdb command's default control timeout from 3s to 10s.
  • debug-hung-script.sh now includes the output of "ctdb scriptstatus" to provide more information.

Important bug fixes

  • Starting CTDB daemon by running ctdbd directly should not remove existing unix socket unconditionally.
  • ctdbd once again successfully kills client processes on releasing public IPs. It was checking for them as tracked child processes and not finding them, so wasn't killing them.
  • ctdbd_wrapper now exports CTDB_SOCKET so that child processes of ctdbd (such as uses of ctdb in eventscripts) use the correct socket.
  • Always use Jenkins hash when creating volatile databases. There were a few places where TDBs would be attached with the wrong flags.
  • Vacuuming code fixes in CTDB 2.2 introduced bugs in the new code which led to header corruption for empty records. This resulted in inconsistent headers on two nodes and a request for such a record keeps bouncing between nodes indefinitely and logs "High hopcount" messages in the log. This also caused performance degradation.
  • ctdbd was losing log messages at shutdown because they weren't being given time to flush. ctdbd now sleeps for a second during shutdown to allow time to flush log messages.
  • Improved socket handling introduced in CTDB 2.2 caused ctdbd to process a large number of packets available on single FD before polling other FDs. Use fixed size queue buffers to allow fair scheduling across multiple FDs.

Important internal changes

  • A node that fails to take/release multiple IPs will only incur a single banning credit. This makes a brief failure less likely to cause node to be banned.
  • ctdb killtcp has been changed to read connections from stdin and 10.interface now uses this feature to improve the time taken to kill connections.
  • Improvements to hot records statistics in ctdb dbstatistics.
  • Recovery daemon now assembles up-to-date node flags information from remote nodes before checking if any flags are inconsistent and forcing a recovery.
  • ctdbd no longer creates multiple lock sub-processes for the same key. This reduces the number of lock sub-processes substantially.
  • Changed the nfsd RPC check failure policy to failover quickly instead of trying to repair a node first by restarting NFS. Such restarts would often hang if the cause of the RPC check failure was the cluster filesystem or storage.
  • Logging improvements relating to high hopcounts and sticky records.
  • Make sure lower level tdb messages are logged correctly.
  • CTDB commands disable/enable/stop/continue are now resilient to individual control failures and retry in case of failures.

ctdb 2.3

Release Notes for ctdb 2.3
July 11, 2013

Changes

User-visible changes

  • 2 new configuration variables for 60.nfs eventscript:
  • CTDB_MONITOR_NFS_THREAD_COUNT
  • CTDB_NFS_DUMP_STUCK_THREADS
See ctdb.sysconfig for details.
  • Removed DeadlockTimeout tunable. To enable debug of locking issues set
  CTDB_DEBUG_LOCKS=/etc/ctdb/debug_locks.sh
  • In overall statistics and database statistics, lock buckets have been updated to use following timings:
  < 1ms, < 10ms, < 100ms, < 1s, < 2s, < 4s, < 8s, < 16s, < 32s, < 64s, >=64s
  • Initscript is now simplified with most CTDB-specific functionality split out to ctdbd_wrapper, which is used to start and stop ctdbd.
  • Add systemd support.
  • CTDB subprocesses are now given informative names to allow them to be easily distinguished when using programs like "top" or "perf".

Important bug fixes

  • ctdb tool should not exit from a retry loop if a control times out (e.g. under high load). This simple fix will stop an exit from the retry loop on any error.
  • When updating flags on all nodes, use the correct updated flags. This should avoid wrong flag change messages in the logs.
  • The recovery daemon will not ban other nodes if the current node is banned.
  • ctdb dbstatistics command now correctly outputs database statistics.
  • Fixed a panic with overlapping shutdowns (regression in 2.2).
  • Fixed 60.ganesha "monitor" event (regression in 2.2).
  • Fixed a buffer overflow in the "reloadips" implementation.
  • Fixed segmentation faults in ping_pong (called with incorrect argument) and test binaries (called when ctdbd not running).

Important internal changes

  • The recovery daemon on stopped or banned node will stop participating in any cluster activity.
  • Improve cluster wide database traverse by sending the records directly from traverse child process to requesting node.
  • TDB checking and dropping of all IPs moved from initscript to "init" event in 00.ctdb.
  • To avoid "rogue IPs" the release IP callback now fails if the released IP is still present on an interface.

ctdb 2.2

Release Notes for ctdb 2.2
May 29, 2013

Changes

User-visible changes

  • The "stopped" event has been removed.
The "ipreallocated" event is now run when a node is stopped. Use this instead of "stopped".
  • New --pidfile option for ctdbd, used by initscript
  • The 60.nfs eventscript now uses configuration files in /etc/ctdb/nfs-rpc-checks.d/ for timeouts and actions instead of hardcoding them into the script.
  • Notification handler scripts can now be dropped into /etc/ctdb/notify.d/.
  • The NoIPTakeoverOnDisabled tunable has been renamed to NoIPHostOnAllDisabled and now works properly when set on individual nodes.
  • New ctdb subcommand "runstate" prints the current internal runstate. Runstates are used for serialising startup.

Important bug fixes

  • The Unix domain socket is now set to non-blocking after the connection succeeds. This avoids connections failing with EAGAIN and not being retried.
  • Fetching from the log ringbuffer now succeeds if the buffer is full.
  • Fix a severe recovery bug that can lead to data corruption for SMB clients.
  • The statd-callout script now runs as root via sudo.
  • "ctdb delip" no longer fails if it is unable to move the IP.
  • A race in the ctdb tool's ipreallocate code was fixed. This fixes potential bugs in the "disable", "enable", "stop", "continue", "ban", "unban", "ipreallocate" and "sync" commands.
  • The monitor cancellation code could sometimes hang indefinitely. This could cause "ctdb stop" and "ctdb shutdown" to fail.

Important internal changes

  • The socket I/O handling has been optimised to improve performance.
  • IPs will not be assigned to nodes during CTDB initialisation. They will only be assigned to nodes that are in the "running" runstate.
  • Improved database locking code. One improvement is to use a standalone locking helper executable - the avoids creating many forked copies of ctdbd and potentially running a node out of memory.
  • New control CTDB_CONTROL_IPREALLOCATED is now used to generate "ipreallocated" events.
  • Message handlers are now indexed, providing a significant performance improvement.

ctdb 2.1

Release Notes for ctdb 2.1
January 8, 2013

Highlights

  • Support for Samba 4.0.0
To use CTDB 2.1 with Samba 3.x, enable Samba3AvoidDeadlocks tunable
  • Set CTDB_BASE in eventscripts, so they can be run easily
  • Clean up orphaned interfaces
  • Do not restart NFS on reconfigure event
  • Fix RSN based recovery of persistent databases to avoid corruption
  • Re-factor and separate IP allocation algorithms

ctdb 2.0

Release Notes for ctdb 2.0
October 30, 2012

This is long overdue CTDB release. There have been numerous code enhancements and bug fixes since the last release of CTDB.

Highlights

  • Support for readonly records (http://ctdb.samba.org/doc/readonlyrecords.txt)
  • Locking API to detect deadlocks between ctdb and samba
  • Fetch-lock optimization to rate-limit concurrent requests for same record
  • Support for policy routing
  • Modified IP allocation algorithm
  • Improved database vacuuming
  • New test infrastructure

Reporting bugs & Development Discussion

Please discuss this release on the samba-technical mailing list or by joining the #ctdb IRC channel on irc.freenode.net.

All bug reports should be filed under CTDB product in the project's Bugzilla database (https://bugzilla.samba.org/).


Download Details

The source code can be downloaded from:

     http://ftp.samba.org/pub/ctdb/

Git repository

      git://git.samba.org/ctdb.git
      http://git.samba.org/?p=ctdb.git;a=summary  (Git via web)

CTDB documentation

       https://ctdb.samba.org/