const classafMongo::MongoConnMgr

sys::Obj
  afMongo::MongoConnMgr

Manages a pool of connections to a MongoDB instance.

Connections are created on-demand and a total of minPoolSize are kept in a pool when idle. Once the pool is exhausted, any operation requiring a connection will block for (at most) waitQueueTimeout waiting for an available connection.

This connection manager is created with the standard Mongo Connection URL in the format:

mongodb://[username:password@]host[:port][/[defaultauthdb][?options]]

Examples:

mongodb://localhost:27017
mongodb://username:password@example1.com/puppies?maxPoolSize=50

If connecting to a replica set then multiple hosts (with optional ports) may be specified:

mongodb://db1.example.net,db2.example.net:2500/?connectTimeoutMS=30000

See https://www.mongodb.com/docs/manual/reference/connection-string/ for details.

On startup() the hosts are queried to find the primary / master node. All read and write operations are performed on the primary node.

When a connection to the master node is lost, all hosts are re-queried to find the new master.

Note this connection manager is safe for multi-threaded / web-application use.

isConnected

Source

Bool isConnected()

Returns true if currently connected to the Master node.

leaseConn

Source

Obj? leaseConn(|MongoConn->Obj? c)

Makes a connection available to the given function.

What ever is returned from the func is returned from the method.

If all connections are currently in use, a truncated binary exponential backoff algorithm is used to wait for one to become free. If, while waiting, the duration specified in waitQueueTimeout expires then a MongoErr is thrown.

All leased connections are authenticated against the default credentials

Any IOErrs thrown in the fn are assumed to be networking errors, and invoke a topology rescan and a Master failover.

log

Source

Log log()

The log instance used to report warnings.

make

Source

new make(Uri connectionUrl, Log? log := null, ActorPool? actorPool := null)

Creates a pooled Mongo Connection Manager.

URL examples:

mongodb://username:password@example1.com/database?maxPoolSize=50
mongodb://example2.com?minPoolSize=10&maxPoolSize=50&ssl=true

If user credentials are supplied, they are used as default authentication for each connection.

See MongoConnUrl for connection URL details.

mongoConnUrl

Source

MongoConnUrl mongoConnUrl()

The parsed Mongo Connection URL.

mongoUrl

Source

Uri? mongoUrl()

Basic details of where this ConnectionManager connects to, for debugging purposes. When connecting to replica sets, this should indicate the primary.

It should not contain any user credentials and should be safe to log.

This value is unavailable (returns null) until startup() is called.

props

Source

Str:Obj? props()

Returns properties and statistics about this connection manager.

stats() // --> [
  "mongoUrl"        : `mongodb://localhost:27017/dbName`,
  "hosts"           : ["localhost", "otherhost"]
  "maxWireVer"      : 7,
  "compression"     : ["zlib", "snappy"]
  "sessionTimeout"  : 30min,
  "numConns"        : 7,
  "numConnsInUse"   : 3,
  "primaryFound"    : true,
]

The keys and data returned are for debug info only and are not guaranteed to exist in 
future driver versions.

runInTxn

Source

Void runInTxn([Str:Obj?]? txnOpts, |Obj? txnFn)

Runs the given fn in a Mongo multi-cmd, multi-collection, transaction. Should the fn complete normally, the transaction is committed. If the fn throws an Err, the transaction is aborted / rolled back.

runInTxn([
  "readConcern"    : [...],
  "writeConcern"   : [...],
  "timeoutMS"      : 10_000,
]) {
  ...
  // do some Mongo stuff
  ...
}

The passed function MUST be idempotent - as it will be re-executed on transient MongoDB server errors.

Note: The obj passed to fn is undefined and should not be used.

setDebug

Source

virtual This setDebug(Bool debugOn := true)

Sets the log level to debug to log all cmd request and responses.

shutdown

Source

This shutdown()

Closes all MongoDB connections.

startup

Source

This startup()

Creates the initial pool and establishes minPoolSize connections with the server.

If a connection URL to a replica set is given (a connection URL with multiple hosts) then the hosts are queried to find the primary. The primary is currently used for all read and write operations.