Performance improvements. Performance for outbound replication from a source cluster to a destination has been improved. CPU utilization on destination clusters has been reduced for better performance.

Improved Error Handling and Logging. More information about documents and the size of documents awaiting replication now available.

UI Improvements for XDCR in the Couchbase Web Console.

Now provide timestamp for when a TAP queue backfill starts. The TAP backfill queue is used to send a snapshot of a vbucket to another node.

Issues: MB-6753

Couchbase Server had created new checkpoints even in the case where empty, current checkpoints were available. The server provided extraneous notifications when various changes to checkpoints ID occurred due to constant polling by XDCR. Now when an empty checkpoint is available, the server uses this checkpoint for additional replication and provide this checkpoint ID to XDCR. The server also pushes a single notification to XDCR when a checkpoint is empty.

Issues: MB-6632

Couchbase Server kept requesting to mark a group of partitions as indexable when they were already marked as indexable, or when they are already correctly marked as unindexable. This triggered redundant effort by processes. It is now fixed.

Issues: MB-6804

During XDCR replication, an incorrect cache-miss-ratio had been displayed in Web Console, and had been returned in response to a cbstats command. We had erroneously incremented ep_bg_fetched for GET_META background fetches. As a fix, we now provide a separate stat for GET_META background fetches.

Issues: MB-6628

Get-and-touch returned incorrect error messages when an error occurs. Get-and-touch now returns ENOENT if key does not exist.

Issues: MB-6840

This enables users to change the disk location of an index without destroying persisted data. You can now set index_path and it will delete an existing index only and create a new disk location for use.

Issues: MB-6423

When you try to automatically failover a node, Couchbase Server will not perform the failover if there are not enough replica vBuckets in the cluster to support the failed node.

Issues: MB-6209

Querying a view during rebalance had resulted in several errors due to the way database storage files were managed and named. We now exclude opening databases that are meant to be excluded from indexing and we now synchronously open databases for indexing to resolve the problem.

Issues: MB-6612

Querying a view on a single node incorrectly returned inconsistent_state error if a bucket is empty. This is corrected.

Issues: MB-6736

Provide additional XDCR information on Logs tab of Couchbase Web Console.

Issues: MB-6888

We added missing checks to state transition requests. Also erroneous error messages had occurred while the server monitored partition in pending transition. This has been corrected.

Issues: MB-6490

The collect_info logs was missing the mapreduce_errors log file. Now this log also contains mapreduce_errors.

Issues: MB-6859

Change the frequency that internal timeouts on Windows were occurring to be more efficient.

Issues: MB-6653

Node rebalance was failing when new nodes were added to the cluster. This occurred due to processes being triggered after defining partitions for indexing. The processes are now being triggered at the correct time.

Issues: MB-6706

Replication had exited with replicator_died message after multiple attempts to update. Problem was caused by using old revision numbers for new database files. Now new database files use new revision numbers, resolving the problem.

Issues: MB-6711

Sporadic failures occurred while running a unit test for testing duplicate items on disk. Test now modified to use less items.

Issues: MB-6647

Keys stored in the access log were not correctly scheduled to load, due to a broken logic for detecting duplicate items. Now keys properly load during warmup from access log.

Issues: MB-6616

Couchbase Server had returned a HTTP 404 error when a node is rebalanced and a client tried to cache a list of nodes for a bucket. Now the server sends a HTTP 302 redirect with the URL of an available node.

Issues: MB-6922

The thread responsible for persisting data in Couchbase Server had been crashing during vBucket state changes. This was caused by not handling file not found exceptions. The cause of the crashes has been fixed.

Issues: MB-6676

Check-and-set value was not returned in response to a successful delete request. Now it is returned as part of the response.

Issues: MB-6661

Server now releases returned document that is being marked deleted. This fixes a rebalance failure where memcached crashes on one of the nodes and rebalance exits with the error: {mover_failed,{badmatch, known macro: {error,closed}}}.

Issues: MB-6806

The Couchbase REST-API has changed to enable you to change the default maximum number of buckets used in a Couchbase cluster. The maximum allowed buckets in this request is 128, however the maximum suggested number of buckets is ten per cluster. This is a safety mechanism to ensure that a cluster does not have resource and CPU overuse due to too many buckets. The following illustrates the endpoint and parameters used:

shell>	curl -X -u admin:password -d maxBucketCount=6 http://ip_address:8091/internalSettings

For this request you need to provide administrative credentials for the cluster. The following HTTP request will be sent:

About to connect() to 127.0.0.1 port 8091 (#0)
Trying 127.0.0.1...
connected
Connected to 127.0.0.1 (127.0.0.1) port 8091 (#0)
Server auth using Basic with user 'Administrator'
POST /internalSettings HTTP/1.1

If Couchbase Server successfully changes the bucket limit for the cluster, you will get a HTTP 200 response:

HTTP/1.1 200 OK
Server: Couchbase Server 2.0.0r_501_gb614829
Pragma: no-cache
Date: Wed, 31 Oct 2012 21:21:48 GMT
Content-Type: application/json
Content-Length: 2
Cache-Control: no-cache

If you provide an invalid number, such as 0, a negative number, or an amount over 128 buckets, you will get this error message:

["Unexpected server error, request logged."]

For more information about setting buckets per cluster via REST-API, see 「クラスタの最大バケットの設定」.

Issues: MB-5684

Automatically prevent a user from creating more than the maximum number of supported buckets in a Couchbase cluster. The default maximum is six.

Issues: MB-5684

Provide cleaner, simplified output on error messages from XDCR replication.

Issues: MB-6763

Incorrect message had been sent in response to a cbstats vkey command. Server had returned the string 'not found' for valid request. Now correct the memcached protocol error is returned. For more information about cbstats, see 「cbstatsツール」.

Issues: MB-6751

Fixed stats vkey status for evicted keys. Stats vkey was returning item_deleted instead of valid for evicted keys. This change fixes that problem.

Issues: MB-6840

cbepctl help options now show option for setting the expiry_pager, a maintenance process for removing deleted items from disk.

Issues: MB-6764

Remove an internal setting dialog used internally by Couchbase for testing consistent views.

Issues: MB-6713

On Window platform, errors occurred trying to update a design document. This is now fixed.

Issues: MB-6653

When consistent views were enabled and rebalance was being performed, the rebalance would fail. This was due to incorrect handling of empty partitions and by accidentally performing disk cleaning before updating partitions which would not be indexed. This is fixed.

Issues: MB-6612

In the past we had displayed several confusing error messages and warnings for XDCR. We had provided low level information in the Couchbase Web Console that is now provided to low files to avoid overwhelming users with information. We were also reporting errors that were actually more appropriately called warnings since they were recoverable issues. We have changed those errors to warning/advisories.

Issues: MB-6934

By default, the server automatically disables flushing data from a source data bucket when XDCR replications exist for that bucket.

Issues: MB-6809

Renamed "XDCR replication queue" in summary section to "XDCR docs to replicate" for clarity.

Issues: MB-6924

Replication via XDCR had experienced performance degradation when a data bucket contained a higher ratio of expired items. This has been fixed by ignoring the expiration time set for an item, SET_WITH_META.

Issues: MB-6662

We have added 3 new outbound operation stats, namely, 1) data replicated, which is amount of data XDCR have replicated to the remote data center through inter- cluster network; 2) active vb replications, which shows the number of ongoing active replications to the remote clusters; 3) waiting vb replications, which is the number of vb replications in the waiting pool to wait for turn to start replication. These stats will be useful for performance monitoring and diagnosis.

Issues: MB-6919

Couchbase Server was dropping connections from client libraries too quickly when a node in a cluster was being rebalanced. Now there will be more delay until a connection is dropped.

Issues: MB-5406

By default, the server automatically disables flushing data from a source data bucket when XDCR replications exist for that bucket.

Issues: MB-6809

Increase maximum number of retries to open the database file.

Issues: MB-6844

Prioritize flushing pending vbuckets over regular vbuckets. This is a performance improvement used for rebalancing buckets that have no views or design docs when consistent view mode is enabled.

Issues: MB-6796

Couchbase Server had experienced a one second delay to mark empty and closed checkpoints on a persistence queue. Performance improvements made to eliminate delay.

Issues: MB-6714

It is not possible to perform an upgrade between Couchbase Server 2.0 pre-releases including beta, or to perform an offline upgrade from Couchbase Server 1.8 to a pre-release or beta of Couchbase Server 2.0. To upgrade between these versions use cbbackup to backup your data, delete the existing installation, install the new version, and restore the stored data.

For more information, see 「バックアップとリストア」, 付録B Couchbase Serverのアンインストール.

Documents identified as Non-JSON stored within Couchbase Server may appear as binary, or text-encoded binary data within the UI.

Issues: MB-7069

During periods of moderate CPU load on the Couchbase Server cluster, you may see warnings that IP address seems to have changed. Unable to listen to node X.X.X.X.

Issues: MB-7115, MB-7238, MB-7228

The cbbackup, cbrestore, and cbtransfer command-line tools require the zlib module for Python to have been installed. If Python was installed from source, you must have enabled zlib using the --with-zlib option during the build process.

Issues: MB-7256

For more information, see 「バックアップとリストア」, 付録B Couchbase Serverのアンインストール.