Metadata-Version: 2.1
Name: couchdb-cluster-admin
Version: 0.6.0
Summary: Utility for managing multi-node couchdb 2.x clusters
Home-page: https://github.com/dimagi/couchdb-cluster-admin
Maintainer: Dimagi
Maintainer-email: dev@dimagi.com
License: BSD License
Description: # couchdb-cluster-admin
        utility for managing multi-node couchdb 2.x clusters
        
        # First, put together a config file for your setup
        
        This will make the rest of the commands simpler to run. Copy the example
        
        ```
        cp config/conf.example.yml config/mycluster.yml
        ```
        
        and then edit it with the details of your cluster.
        
        # Setting up a local cluster to test on
        
        If you have docker installed you can just run
        
        ```bash
        docker build -t couchdb-cluster - < docker-couchdb-cluster/Dockerfile
        ```
        
        to build the cluster image (based on klaemo/couchdb:2.0-dev) and then run
        
        ```bash
        docker run --name couchdb-cluster \
          -p 15984:15984 \
          -p 15986:15986 \
          -p 25984:25984 \
          -p 25986:25986 \
          -p 35984:35984 \
          -p 35986:35986 \
          -p 45984:45984 \
          -p 45986:45986 \
          -v $(pwd)/data:/usr/src/couchdb/dev/lib/ \
          -t couchdb-cluster \
          --with-admin-party-please \
          -n 4
        ```
        
        to start a cluster with 4 nodes. The nodes' data will be persisted to `./data`.
        
        To run the tests (which require this docker setup), download and install https://github.com/sstephenson/bats
        
        ```bash
        git clone https://github.com/sstephenson/bats.git
        cd bats
        ./install.sh /usr/local  # or wherever on your PATH you want to install this
        ```
        
        and then
        
        ```bash
        docker start couchdb-cluster  # make sure this is running and localhost:15984 is receiving pings
        bats test/
        ```
        
        # Optional: Set password in environment
        
        If you do not wish to specify your password every time you run a command,
        you may put its value in the `COUCHDB_CLUSTER_ADMIN_PASSWORD` environment variable like so:
        
        ```
        read -sp Password: PW
        ```
        
        Then, for all commands below prefex the command with `COUCHDB_CLUSTER_ADMIN_PASSWORD=$PW`, e.g.
        
        ```
        COUCHDB_CLUSTER_ADMIN_PASSWORD=$PW python couchdb-admin-cluster/describe.py --conf mycluster.yml
        ```
        
        # Get a quick overview of your cluster
        
        Now you can run
        
        ```
        python couchdb_cluster_admin/describe.py --conf config/mycluster.yml
        ```
        
        to see an overview of your cluster nodes and shard allocation.
        For example, in the following output:
        
        ```
        Membership
        	cluster_nodes:	couch3	couch1	couch4	couch2
        	all_nodes:	couch3	couch1	couch4	couch2
        Shards
        	                   00000000-1fffffff  20000000-3fffffff  40000000-5fffffff  60000000-7fffffff  80000000-9fffffff  a0000000-bfffffff  c0000000-dfffffff  e0000000-ffffffff
        	mydb                    couch1             couch1             couch1             couch1             couch1             couch1             couch1             couch1
        	my_second_database      couch1             couch1             couch1             couch1             couch1             couch1             couch1             couch1
        ```
        
        you can see that while there are four nodes,
        all shards are currently assigned only to the first node.
        
        # Help estimating shard allocation
        
        In order to plan out a shard reallocation, you can run the following command:
        
        ```bash
        python couchdb_cluster_admin/suggest_shard_allocation.py --conf config/mycluster.yml --allocate couch1:1 couch2,couch3,couch4:2
        ```
        
        The values for the `--allocate` arg in the example above should be interpreted as
        "Put 1 copy on couch1, and put 2 copies spread across couch2, couch3, and couch4".
        
        The output looks like this:
        
        ```
        couch1	57.57 GB
        couch2	42.15 GB
        couch3	36.5 GB
        couch4	36.5 GB
                             00000000-1fffffff     20000000-3fffffff     40000000-5fffffff     60000000-7fffffff     80000000-9fffffff     a0000000-bfffffff     c0000000-dfffffff     e0000000-ffffffff
        mydb                couch1,couch2,couch4  couch1,couch2,couch3  couch1,couch3,couch4  couch1,couch2,couch4  couch1,couch2,couch3  couch1,couch3,couch4  couch1,couch2,couch4  couch1,couch2,couch3
        my_second_database  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4  couch1,couch3,couch4
        ```
        
        Note, the reallocation does not take into account the current location of shards,
        so it is much more useful in the situation that you're moving from a single-node cluster
        to a multi-node cluster than it is in the situation where you're adding one more node to a multi-node cluster.
        In the example above, couch1 would be the single-node cluster and couch2, couch3, and couch4
        form are the multi-node cluster–to-be. You can imagine that after implementing
        the shard allocation suggested here, we might remove all shards from couch1 and remove it from the cluster.
        
        Note also that there is no guarantee that the "same" shard of different databases will go to the same node;
        each (db, shard)-pair is treated as an independent unit when making computing an even shard allocation.
        In this example there are only a few dbs and shards; when shards * dbs is high,
        this process can be quite good at evenly balancing your data across nodes.
        
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Description-Content-Type: text/markdown
