Superseded by rave-level. Please see Frequently Asked Questions.

Normally with level, when you try to open a database handle from more than one process you will get a locking error:

events.js:72 throw er; // Unhandled 'error' event ^ OpenError: IO error: lock /home/substack/projects/level-party/example/data/LOCK: Resource temporarily unavailable at /home/substack/projects/level-party/node_modules/level/node_modules/level-packager/node_modules/levelup/lib/levelup.js:114:34 

With level-party, the database open will automatically drop down to using multilevel over a unix socket using metadata placed into the level data directory transparently.

This means that if you have 2 programs, 1 that gets:

constlevel=require('level-party')constdb=level(__dirname+'/data',{valueEncoding: 'json'})setInterval(function(){db.get('a',function(err,value){console.log('a=',value)})},250)

And 1 that puts:

constlevel=require('level-party')constdb=level(__dirname+'/data',{valueEncoding: 'json'})constn=Math.floor(Math.random()*100000)setInterval(function(){db.put('a',n+1)},1000)

and you start them up in any order, everything will just work! No more IO error: lock exceptions.

$ node put.js & sleep 0.2; node put.js & sleep 0.2; node put.js & sleep 0.2; node put.js & sleep 0.2 [1] 3498 [2] 3502 [3] 3509 [4] 3513 $ node get.js a= 35340 a= 31575 a= 37639 a= 58874 a= 35341 a= 31576 $ node get.js a= 35344 a= 31579 a= 37643 a= 58878 a= 35345 ^C 

Hooray!

level-party does seamless failover. This means that if you create a read-stream and the leader goes down while you are reading that stream level-party will resume your stream on the new leader.

This disables leveldb snapshotting so if your app relies on this you should disable this by setting opts.retry = false:

constdb=level('./data',{retry: false})// will not retry streams / gets / puts if the leader goes down

level-party works on Windows as well using named pipes.

The arguments are exactly the same as level. You will sometimes get a real leveldb handle and sometimes get a multileveldown handle back in the response.

With npm do:

npm install level-party 

Level/party is an OPEN Open Source Project. This means that:

Individuals making significant and valuable contributions are given commit-access to the project to contribute as they see fit. This project is more like an open wiki than a standard guarded open source project.

See the Contribution Guide for more details.

Support us with a monthly donation on Open Collective and help us continue our work.

MIT