--- title: Charmhub | Deploy MongoDB using Charmhub - The Open Operator Collection description: Deploy the latest version of MongoDB on any cloud. url: https://charmhub.io/mongodb/libraries/mongos --- # MongoDB [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") * [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") * [Databases](https://charmhub.io/?filter=databases) Platform: 24.04 22.04 6/stable 265 ``` juju deploy mongodb --channel 6/stable ``` [Learn to deploy on juju >](https://juju.is/docs/juju/manage-applications) [Toggle side navigation](https://charmhub.io/mongodb/libraries/mongos#drawer) ## charms.mongodb.v1.mongos * [*Docstrings*Docstrings](https://charmhub.io/mongodb/libraries/mongos) [*Code*Source code](https://charmhub.io/mongodb/libraries/mongos/source-code) * + Download Fetch library ``` charmcraft fetch-lib charms.mongodb.v1.mongos ``` [Download mongos.py](https://charmhub.io/mongodb/libraries/mongos/download) + *Last updated* 21 Aug 2024 + *Revision* Library version 1.7 Code for interactions with MongoDB. --- Index * [class NotEnoughSpaceError](https://charmhub.io/mongodb/libraries/mongos#notenoughspaceerror) * [class ShardNotInClusterError](https://charmhub.io/mongodb/libraries/mongos#shardnotinclustererror) * [class ShardNotPlannedForRemovalError](https://charmhub.io/mongodb/libraries/mongos#shardnotplannedforremovalerror) * [class NotDrainedError](https://charmhub.io/mongodb/libraries/mongos#notdrainederror) * [class BalancerNotEnabledError](https://charmhub.io/mongodb/libraries/mongos#balancernotenablederror) * [class MongosConnection](https://charmhub.io/mongodb/libraries/mongos#mongosconnection) * + [def \_\_init\_\_( self, config, uri, direct)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-__init__) * + [def get\_shard\_members( self)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-get_shard_members) * + [def add\_shard( self, shard\_name, shard\_hosts, shard\_port)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-add_shard) * + [def pre\_remove\_checks( self, shard\_name)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-pre_remove_checks) * + [def start\_and\_wait\_for\_balancer( self)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-start_and_wait_for_balancer) * + [def remove\_shard( self, shard\_name)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-remove_shard) * + [def get\_databases\_for\_shard( self, primary\_shard)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-get_databases_for_shard) * + [def is\_any\_draining( self, ignore\_shard)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-is_any_draining) * + [def is\_ready( self)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-is_ready) * + [def are\_all\_shards\_aware( self)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-are_all_shards_aware) * + [def is\_shard\_aware( self, shard\_name)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-is_shard_aware) * + [def get\_db\_size( self, database\_name, primary\_shard)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-get_db_size) * + [def get\_shard\_with\_most\_available\_space( self, shard\_to\_ignore)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-get_shard_with_most_available_space) * + [def get\_draining\_shards( self)](https://charmhub.io/mongodb/libraries/mongos#mongosconnection-get_draining_shards) #### class NotEnoughSpaceError Description Raised when there isn't enough space to movePrimary. None #### class ShardNotInClusterError Description Raised when shard is not present in cluster, but it is expected to be. None #### class ShardNotPlannedForRemovalError Description Raised when it is expected that a shard is planned for removal, but it is not. None #### class NotDrainedError Description Raised when a shard is still being drained. None #### class BalancerNotEnabledError Description Raised when balancer process is not enabled. None #### class MongosConnection In this class we create connection object to Mongos. Description Real connection is created on the first call to Mongos. Delayed connectivity allows to firstly check database readiness and reuse the same connection for an actual query later in the code. Connection is automatically closed when object destroyed. Automatic close allows to have more clean code. Note that connection when used may lead to the following pymongo errors: ConfigurationError, ConfigurationError, OperationFailure. It is suggested that the following pattern be adopted when using MongoDBConnection: with MongoMongos(self.\_mongos\_config) as mongo: try: mongo. except ConfigurationError, OperationFailure: Methods MongosConnection. \_\_init\_\_( *self* , config: MongoConfiguration , uri , direct ) A MongoDB client interface. Arguments config MongoDB Configuration object. uri allow using custom MongoDB URI, needed for replSet init. direct force a direct connection to a specific host, avoiding reading replica set configuration and reconnection. MongosConnection. get\_shard\_members( *self* ) Gets shard members. Description Returns: A set of the shard members as reported by mongos. Raises: ConfigurationError, OperationFailure MongosConnection. add\_shard( *self* , shard\_name , shard\_hosts , shard\_port ) Adds shard to the cluster. Description Raises: ConfigurationError, OperationFailure MongosConnection. pre\_remove\_checks( *self* , shard\_name ) Performs a series of checks for removing a shard from the cluster. Description Raises ConfigurationError, OperationFailure, NotReadyError, ShardNotInClusterError, BalencerNotEnabledError MongosConnection. start\_and\_wait\_for\_balancer( *self* ) Turns on the balancer and waits for it to be running. Description Starting the balancer doesn't guarantee that is is running, wait until it starts up. Raises: BalancerNotEnabledError MongosConnection. remove\_shard( *self* , shard\_name: str ) Removes shard from the cluster. Description Raises: ConfigurationError, OperationFailure, NotReadyError, NotEnoughSpaceError, ShardNotInClusterError, BalencerNotEnabledError MongosConnection. get\_databases\_for\_shard( *self* , primary\_shard ) Returns a list of databases using the given shard as a primary shard. Description In Sharded MongoDB clusters, mongos selects the primary shard when creating a new database by picking the shard in the cluster that has the least amount of data. This means that: 1. There can be multiple primary shards in a cluster. 2. Until there is data written to the cluster there is effectively no primary shard. MongosConnection. is\_any\_draining( *self* , ignore\_shard: str ) Returns true if any shard members is draining. Arguments sc\_status current state of shard cluster status as reported by mongos. ignore\_shard shard to ignore Description Checks if any members in sharded cluster are draining data. MongosConnection. is\_ready( *self* ) Is mongos ready for services requests. Description Returns: True if services is ready False otherwise. Retries over a period of 60 seconds times to allow server time to start up. Raises: ConfigurationError, ConfigurationError, OperationFailure MongosConnection. are\_all\_shards\_aware( *self* ) Description Returns True if all shards are shard aware. None MongosConnection. is\_shard\_aware( *self* , shard\_name: str ) Description Returns True if provided shard is shard aware. None MongosConnection. get\_db\_size( *self* , database\_name , primary\_shard ) Description Returns the size of a DB on a given shard in bytes. None MongosConnection. get\_shard\_with\_most\_available\_space( *self* , shard\_to\_ignore ) Returns the shard in the cluster with the most available space and the space in bytes. Description Algorithm used was similar to that used in mongo in `selectShardForNewDatabase`: https://github.com/mongodb/mongo/blob/6/0/src/mongo/db/s/config/sharding\_catalog\_manager\_database\_operations.cpp#L68-L91 MongosConnection. get\_draining\_shards( *self* ) Description Returns a list of the shards currently draining. None