Apache CouchDB 1.2.0 has been released and is available for download.
Grab your copy here:
Windows packages are now available. Grab them at the same download link.
This release also coincides with a revamped project homepage!
This is a big release with lots of updates. Please also note that this release contains breaking changes.
These release notes are based on the NEWS file.
Added a native JSON parser
Performance critical portions of the JSON parser are now implemented in C. This improves latency and throughput for all database and view operations. We are using the fabulous yajl library.
Optional file compression (database and view index files)
This feature is enabled by default.
All storage operations for databases and views are now passed through Google’s snappy compressor. The result is simple: since less data has to be transferred from and to disk and through the CPU & RAM, all database and view accesses are now faster and on-disk files are smaller. Compression can be changed to gzip compression with options that specify the compression ratio or it can be fully disabled as well.
Several performance improvements, especially regarding database writes and view indexing
Combined with the two preceding improvements, we made some less obvious algorithmic improvements that take the Erlang runtime system into account when writing data to databases and view index files. The net result is much improved performance for most common operations including building views.
The JIRA ticket (COUCHDB-976) has more information.
Performance improvements for the built-in changes feed filters
The security system got a major overhaul making it way more secure to run CouchDB as a public database server for CouchApps. Unfortunately we had to break a bit of backwards compatibility with this, but we think it is well worth the trouble.
Documents in the
_usersdatabase can no longer be read by everyone
Documents in the
_usersdatabases can now only be read by the respective authenticated user and administrators. Before, all docs were world-readable including their password hashes and salts.
Confidential information in the
_replicationdatabase can no longer be read by everyone
Similar to documents in the
_usersdatabase, documents in the
_replicatordatabase now get passwords and OAuth tokens stripped when read by a user that is not the creator of the replication or an administrator.
Password hashes are now calculated by CouchDB instead of the client
Previously, CouchDB relied on the client to hash and salt the user’s password. Now, it accepts plain text passwords and hashes them before they are committed to disk, following traditional best practices.
Allow persistent authentication cookies
Cookie based authentication can now keep a user logged in over a browser restart.
OAuth secrets can now be stored in the users system database
This is better for managing large numbers of users and tokens than the old, clumsy way of storing OAuth tokens in the configuration system and configuration system.
erlang_oauthlibrary to the latest version
The Erlang library that handles OAuth authentication has been updated to the latest version.
This makes building CouchDB on certain platforms easier.
data_sizeproperty to database and view group information URIs
With this you can now calculate how much actual data is stored in a database file or view index file and compare it with the file size that is already being reported. The difference is CouchDB-specific overhead most of which can be reclaimed during compaction. This is used to power the automatic compaction feature (see below).
Added optional field
since_seqto replication objects/documents
This allows you to start a replication from a certain database update sequence instead from the start.
_active_tasksAPI now exposes more granular fields for each task type
The replication and compaction tasks, e.g. report their progress in the task info.
Added built-in changes feed filter
With this you can use a view’s map function as a changes filter instead of duplicating.
Added support for automatic compaction
This feature is disabled by default, but it can be enabled in the configuration page in Futon or the
Compaction is a regular maintenance task for CouchDB. This can now be automated based on multiple variables:
- A threshold for the
disk_sizeratio (say 70%)
- A time window specified in hours and minutes (e.g 01:00-05:00)
Compaction can be cancelled if it exceeds the closing time. Compaction for views and databases can be set to run in parallel, but that is only useful for setups where the database directory and view directory are on different disks.
In addition, if there’s not enough space (2 ×
data_size) on the disk to complete a compaction, an error is logged and the compaction is not started.
- A threshold for the
A new replicator implementation that offers more performance and configuration options
The replicator has been rewritten from scratch. The new implementation is more reliable, faster and has more configuration than the previous implementation. If you have had any issues with replication in previous releases, we strongly recommend giving 1.2.0 a spin.
Configuration options include:
- Number of worker processes
- Batch size per worker
- Maximum number of HTTP connections
- Number of connection retries
default.inifor the full list of options and their default values.
This allows you to fine-tune replication behaviour tailored to your environment. A spotty mobile network connection can benefit from a single worker process and small batch sizes to reliably, albeit slowly, synchronise data. A full-duplex 10GigE server-to-server connection on a LAN can benefit from more workers and higher batch sizes. The exact values depend on your particular setup and we recommend some experimentation before settling on a set of values.
Statusscreen (active tasks) now displays two new task status fields:
Simpler replication cancellation
Running replications can now be cancelled with a single click.
Log correct stack trace in all cases
In certain error cases, CouchDB would return a stack trace from the log system itself and hide the real error. Now CouchDB always returns the correct error.
Improvements to log messages for file-related errors
CouchDB requires correct permissions for a number of files. Error messages related to file permission errors were not always obvious and are now improved.
- Fixed old index file descriptor leaks after a view cleanup
- Fixes to the
_changesfeed heartbeat option when combined with a filter. It affected continuous pull replications with a filter
- Fix use of OAuth with VHosts and URL rewriting
requested_pathproperty of query server request objects now has the path requested by clients before VHosts and rewriting
- Fixed incorrect reduce query results when using pagination parameters
icu_driverwork with Erlang R15B and later
- Improvements to the build system and etap test suite
- Avoid invalidating view indexes when running out of file descriptors
This release contains breaking changes:
It is very important that you understand these changes before you upgrade.
See the CHANGES file and the Git commit log for more information.