CouchDB Weekly News, June 26

Releases

Apache CouchDB 1.6.0 released

This is a feature release. Download link | Release notes

Blog Posts

Weekly CouchDB meeting – summary

  • 1.6.0 released: We encourage you to get your own CouchDB upgrade here
  • Welcome new committer: Lena Reinhard has been elected as a new CouchDB Committer
  • BigCouch merge: The merge has been done, currently .couch file migrations are being tested from 1.1.2 onwards for the latest point releases. See the call for help with testing and details about the testing procedure here.
  • CouchDB Blog: There’ll be a new CouchDB Blog soon (see email)
  • L10n (Localisation): Help with translation of CouchDB docs is highly appreciated! See “get involved” section below for details
  • AdvocateHub: The Marketing Team is planning the implementation of a new tool for community care, a timeline has been drafted (see email)

Major Discussions

Fauxton Dashboard (see thread)

We’re about to start working on adding Show + List functions into the Fauxton Dashboard. If there is anything you would like to see added in the functionality, please let us know on dev@ mailing list.

How to get the BigCouch Merge + Fauxton running for testing (see thread)

How to get the BigCouch branch and Fauxton running for testing. The detailed description can be found here. Please help us with the tests, and post any bugs you notice to dev@ Mailing List. Your help is highly appreciated.

Error with complex viewings and doc size (see thread)

Setup: database with 10 documents, some >1GB. When the user tried to do relatively complex viewings, an error occured. They asked if there was a way for the viewing to bother only with a specified doc in the database and not go through all the doc. In addition, they asked why even with smaller docs the views take quite long.

Approaches:

  • Very large docs should be broken into smaller ones. Depending on the application and the data model, this can be recommendable. In any case, files of around 1GB size should be avoided, if possible.
  • The views get constructed at the time of first access after a new doc is uploaded to the database (and every time a doc is updated). So, in normal service this should be pretty fast.

What is considered idle in CouchDB? (see thread)

A user referred to the description of max_db_open where it says “CouchDB reference counts database accesses internally and will close idle databases when it must.” They asked what’s considered idle in CouchDB and if the idle time was configurable.

Answer:

  • The database considers idle by active references to it and by related active operations (like compaction) (see this post)
  • CouchDB uses LRU cache to manage open databases and frees idle by demand (see this post and this one).

There is no need for specific configuration.

Effects of changing the limit of max_dbs_open (see thread)

Setup: around 90K+ databases. max_dbs_open was set to 100K which led to a high memory usage. Thus, max_dbs_open was reduced to 50K. This reduced memory usage but led to a lot of opening and closing index in the log file and according to the change feed, only a quite low number of databases is being changed at all time.

Answer: CouchDB references to a database even there is no client attached to it. It will hold databases open up to the limit of max_dbs_open. If a request goes to a database not open, then the oldest database is closed to ensure that the total remains at or below the max_dbs_open setting. So CouchDB will keep 50,000 databases open at once with this setup, regardless of whether clients are making requests to them. If the user wants fewer databases open at once, max_dbs_open should be lowered.

Releases in the CouchDB Universe

  • express-user-couchdb 0.3.0 – An express app module connected to couchdb _users table
  • sails-couchdb-orm 0.10.2 – CouchDB adapter for Sails
  • couch-login 1.0.1 – A module for doing logged-in requests to a CouchDB server
  • frugal-couch 0.1.0 – Allows minimization of the number of HTTP requests to CouchDB
  • express-couchdb-fs 0.3.4 – An express module that adds a CouchDB file service API to any express app
  • slipcover 0.2.4 – Lite wrapper for CouchDB
  • http-replay 0.1 – Library to replay and compare HTTP requests and responses, e.g. to record CouchDB replication and replay that against another backend for testing; includes filtering of responses
  • ionic-pouchdb-todo – A simple Ionic Todo app with a PouchDb local storage backend configured to sync with a CouchDB installation
  • Cloudant Query – offering a declarative way to define and query indexes on the database. For more information, see also this post.

Opinions and other News in the CouchDB Universe

Use Cases, Questions and Answers

no public answer yet:

For more new questions about CouchDB, see these search results.

Get involved!

If you want to get into working on CouchDB:

  • Help test BigCouch file migration for .couch files with your personal databases – you’ll find all details on the testing procedure here
  • We have an infinite number of open contributor positions on CouchDB. Submit a pull request and join the project!
  • Do you want to help moving the CouchDB docs translation forward? We’d love to have you in our L10n team! See our current status and languages we’d like to provide CouchDB docs in on this page. If you’d like to help, don’t hesitate to contact the L10n mailing list on l10n@couchdb.apache.org or ping Andy Wenk (awenkhh on IRC).

We’d be happy to have you!

New Committers and PMC Members

Events

Job opportunities for people with CouchDB skills

… and also in the news

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