Couchbase Server 1.8 is the updated and rebranded release of Membase Server.
To browse or submit new issues, see Couchbase Server Issues Tracker.
In line with the rebranding and name changes, there are some significant changes to the following areas of this release:
Directory Changes
Couchbase Server is now installed into a
couchbase directory, for example on
Linux the default installation directory is
/opt/couchbase instead of
/opt/membase.
During an upgrade, the location of your data files will not be modified.
Command Changes
The name of many of the core commands provided with Couchbase Server have been renamed, with the existing scripts deprecated. For example, the backup command mbbackup in Membase Server is now called cbbackup. See the full release note entry below for more detailed information.
New Features and Behaviour Changes in 1.8.0
Ubuntu 9.x is no longer a supported platform and support will be removed in a future release.
Issues: MB-2506; Tags: deprecated
The SYNC protocol command has been
deprecated. Applications and solutions should no longer use the
SYNC command. The command will be removed
entirely in a future version.
Tags: deprecation
Ubuntu 8.x is no longer a supported platform.
Issues: MB-2506; Tags: removal
Internet Explorer 7 as a supported browser for the Couchbase Web Admin Console is now deprecated, and support will be removed entirely in a future release.
Tags: deprecation
Allow disk write queue upper limit to be modified at runtime.
Issues: MB-4418
Red Hat/CentOS 5.4 is no longer a supported platform and will be removed entirely in a future release.
Issues: MB-2506; Tags: deprecated
The following command-line tools have been deprecated and replaced with the corresponding tool as noted in the table below.
| Deprecated Tool | Replacement Tool |
|---|---|
| membase | couchbase-cli |
| mbadm-online-restore | cbadm-online-restore |
| mbadm-online-update | cbadm-online-update |
| mbadm-tap-registration | cbadm-tap-registration |
| mbbackup-incremental | cbbackup-incremental |
| mbbackup-merge-incremental | cbbackup-merge-incremental |
| mbbackup | cbbackup |
| mbbrowse_logs | cbbrowse_logs |
| mbcollect_info | cbcollect_info |
| mbdbconvert | cbdbconvert |
| mbdbmaint | cbdbmaint |
| mbdbupgrade | cbdbupgrade |
| mbdumpconfig.escript | cbdumpconfig.escript |
| mbenable_core_dumps.sh | cbenable_core_dumps.sh |
| mbflushctl | cbflushctl |
| mbrestore | cbrestore |
| mbstats | cbstats |
| mbupgrade | cbupgrade |
| mbvbucketctl | cbvbucketctl |
Using a deprecated tool will result in a warning message that the tool is deprecated and will no longer be supported.
For more information, see Chapter 7, Command-line Interface for Administration.
Tags: deprecation
The membase bucket type has been deprecated.
The couchbase bucket type should be used
instead to select the balanced, persistent and replicated
buckets supported by a Couchbase cluster.
For more information, see Section 10.6, “Buckets”.
Tags: deprecation
Cluster Operations
Unclassified
Installer dependencies on RHEL 5.4 have been updated.
Issues: MB-4561
Installation of Membase on Amazon Linux would fail.
Issues: MB-3419
Rebalancing process might hang when adding or removing nodes in a large cluster where client load is running.
Unable to create a default bucket using membase-cli.
Issues: MB-4453
The ep_num_not_my_vbuckets stat doesn't
reset.
Issues: MB-3852
Decreased memory usage by coalesce checkpoints in the replica
side if item persistence is slower. Server will maintain only
two replica checkpoints for each vbucket.
Issues: MB-4578
Fixed a case where there are two replicas where replication cursor would get stuck and slave node didn't replicate the data into the other node in the replication chain.
Issues: MB-4461
Selecting the master node during rolling upgrade where there are different membase/couchbase servers in the cluster.
Issues: MB-4592
Installation and Upgrade
Running Couchbase as the root may cause
problems, but may not produce suitable warnings. Do not run as
the root user. Note that this is not the same
as installing, which needs to be done by
root.
Issues: MB-1475
Known issues when Couchbase runs out of disk space.
Workaround: Monitor your system resources closely and ensure that the Couchbase nodes don't run out of disk space.
Issues: MB-3158
Large changes in wall-clock time negatively affect disk persistence ability and GUI display.
Workaround: Use NTP to keep systems synchronized and start Couchbase service after such synchronization has taken place.
Memcached process is not shutdown quickly with a high disk write queue.
Workaround: Make sure your disk write queue is as low as possible (or 0) before shutting down the service.
Issues: MB-3628
The Linux installer tries to start couchbase-server and fails. This warning can safely be ignored.
Issues: MB-3797
Cluster Operations
Some known issues when rebalancing with a very high ratio of data on disk versus data in RAM.
Workaround: Use more nodes than less to better distribute the on-disk data.
When using Moxi in a cluster using haproxy,
it's possible for a memory leak to cause a problem in Moxi when
the topology appears to change. The problem is due to
haproxy disabling open connections,
particularly those used for management, that Moxi may have open,
but not using. The haproxy closes these open
connections, which moxi identifies as
topology changes. The problem is particularly prevalent when
using the balance roundrobin load balancing
type.
Workaround: There are two possible workarounds to prevent the memory leak in moxi:
Use balance source load balancing mode
within haproxy. This reduces the effect
of haproxy closing the open network
ports.
Increase the network timeouts in haproxy. You can do this by editing the haproxy configuration file and adding the following two lines:
timeout client 300000 timeout server 300000
The above sets a 5 minute timeout. You can increase this to a larger number.
Issues: MB-4896
Command-line Tools
The cbrestore command sometimes shows a Python interrupt error. This should only happen at the very end of the restore and does not affect the data being inserted.
Issues: MB-3804
The backup commands cbbackup (formerly
mbbackup may fail to work correctly unless
run as couchbase or
membase user.
Workaround:
Run as couchbase or
membase user.
Issues: MB-4614
Unclassified
An imbalanced cluster situation can occur during a rebalance if the cluster has been up for a short period of time (because of start or restart of the cluster), when there is a low number of stored items (less than 500k).
Issues: MB-4595; Tags: rebalance
Scripts and tools supplied with Couchbase Server require Python 2.6. You may need to upgrade your Python installation.
Issues: MB-4667
The ejectNode operation is possibly dangerous
to active servers.
Workaround:
Only use ejectNode on nodes not currently
responsible for any vbuckets.
Issues: MB-3423
UDP access blocked by malformed request
Performing a rolling upgrade from version 1.7.1, might cause rebalance to stick and fail to complete successfully.
Workaround: You can perform a in-place upgrade (shutdown the entire cluster, upgrade, and restart) to get round this issue.
Issues: MB-4615; Tags: incompatibility, rebalance, upgrade
A rebalance issue may occur when removing a node and adding a replacement node. The backfill statistics for the rebalance may show that there are no further items to be transferred, but the rebalance process hangs.
Issues: MB-4864