A command-line utility to calculate the difference between two Cloudant/CouchDB datbases. It operates in one of three modes
- default mode - gets a list of document ids and winning revision tokens for each database and "diffs" them using the
diffcommand. In this mode, if the two databases are deemed equal then they have the same number of documents with the same content up the same revision number. There maybe differences in conflicting revisions. If you are interested in conflict data too, then use
--quick- gets the count of documents and deleted documents from each database - if they match then the two databases are deemed to be the same. This is the quickest but least accurate mode of operation.
--conflicts- same as default mode but also includes revision tokens of non-winning revisions i.e. conflicts. This is the slowest option because couchdiff has to stream the whole changes feed including the document bodies
--unified- outputs the diff in unified format
This tool relies on two universal command-line tools
sortthe *nix command-line tool that sorts text files
diffthe *nix` command-line tool that calculates the difference between text files
The output of this tool is the output of the final
diff step - the difference between the two databases.
This is a Node.js app distributed using the
> npm install -g couchdiff
To calculate the differences between two databases, call
couchdiff with two URLs. The URLs
should include credentials where required, and the database name at the end. Either 'http' or
'https' protocols are supported:
> couchdiff http://localhost:5984/mydb1 http://localhost:5984/mydb2 spooling changes... sorting... calculating difference... 2c2 < 1000543/1-3256046064953e2f0fdb376211fe78ab --- > 1000543/2-7d93e4800a6479d8045d192577cff4f7
The above output shows that document id
1000543 differs in the two databases.
You can use a combination of local and remote databases:
> couchdiff http://localhost:5984/mydb https://U:P@myhost.cloudant.com/mydb spooling changes... sorting... calculating difference...
In this case both databases are identical.
A quicker, but less thorough check can be performed by adding the
> couchdiff --quick http://localhost:5984/mydb1 http://localhost:5984/mydb2 Both databases have the same number of docs and deletions
Quick mode only checks the number of documents and deleted documents in each database, not the revision tokens of each document.
A slower, but very thorough check can be performed by adding the
--conflicts option which will return differences
in the databases not only on the "winning revisions" but in any conflicted documents too:
> couchdiff --conflicts http://localhost:5984/mydb1 http://localhost:5984/mydb2 spooling changes... sorting... calculating difference... 1c1 < mydoc/1-25f9b97d75a648d1fcd23f0a73d2776e/1-icecream --- > mydoc/1-25f9b97d75a648d1fcd23f0a73d2776e/2-7942b2ce39cc4dd85f1809c1756a40c9
- 0 - both databases are the same
- 1 - insufficient number of parameters
- 2 - invalid URL
- 3 - both databases are different
This is an open-source tool released under the Apache-2.0 license. Please feel free to use it, raise issues or contribute pull requests.