module `tarantool.connection_pool`¶

This module provides API for interaction with Tarantool servers cluster.

class tarantool.connection_pool.ConnectionPool(addrs, user=None, password=None, socket_timeout=None, reconnect_max_attempts=0, reconnect_delay=0, connect_now=True, encoding='utf-8', call_16=False, connection_timeout=None, strategy_class=<class 'tarantool.connection_pool.RoundRobinStrategy'>, refresh_delay=1, fetch_schema=True)¶

Represents the pool of connections to a cluster of Tarantool servers.

To work with ConnectionPool, box.info must be callable for the user on each server.

ConnectionPool is best suited to work with a single replicaset. Its API is the same as a single server Connection, but requests support mode parameter (a tarantool.Mode value) to choose between read-write and read-only pool instances:

>>> resp = conn.select('demo', 'AAAA', mode=tarantool.Mode.PREFER_RO)
>>> resp
- ['AAAA', 'Alpha']

Parameters

addrs¶ (list) –

List of dictionaries describing server addresses:

{
    "host': "str" or None,     # mandatory
    "port": int or "str",      # mandatory
    "transport": "str",        # optional
    "ssl_key_file": "str",     # optional
    "ssl_cert_file": "str",    # optional
    "ssl_ca_file": "str",      # optional
    "ssl_ciphers": "str"       # optional
    "ssl_password": "str",     # optional
    "ssl_password_file": "str" # optional
    "auth_type": "str"         # optional
}

Refer to corresponding Connection parameters.

user¶ – Refer to user. The value is used for each connection in the pool.
password¶ – Refer to password. The value is used for each connection in the pool.
socket_timeout¶ – Refer to socket_timeout. The value is used for each connection in the pool.
reconnect_max_attempts¶ – Refer to reconnect_max_attempts. The value is used for each connection in the pool. Be careful: it is internal Connection reconnect unrelated to pool reconnect mechanisms.
reconnect_delay¶ – Refer to reconnect_delay. The value is used for each connection in the pool. Be careful: it is internal Connection reconnect unrelated to pool reconnect mechanisms.
connect_now¶ (bool, optional) – If True, connect to all pool servers on initialization. Otherwise, you have to call connect() manually after initialization.
encoding¶ – Refer to encoding. The value is used for each connection in the pool.
call_16¶ – Refer to call_16. The value is used for each connection in the pool.
connection_timeout¶ (float, optional) – Refer to connection_timeout. The value is used for each connection in the pool.
strategy_class¶ (StrategyInterface, optional) – Strategy for choosing a server based on a request mode. Defaults to the round-robin strategy.
refresh_delay¶ – Minimal time between pool server box.info.ro status background refreshes, in seconds.
fetch_schema¶ – Refer to fetch_schema.

Raise

ConfigurationError, Connection exceptions

call(func_name, *args, mode=None, on_push=None, on_push_ctx=None)¶

Execute a CALL request on the pool server: call a stored Lua function. Refer to call().

Parameters

func_name¶ – Refer to func_name.
args¶ – Refer to args.
mode¶ (Mode) – Request mode.
on_push¶ – Refer to on_push.
on_push_ctx¶ – Refer to on_push_ctx.

Return type

Response

Raise

ValueError, call() exceptions

close()¶: Stop request processing, close each connection in the pool.

connect()¶

Create a connection to each address specified on initialization and start background process threads for them. There is no need to call this method explicitly until you have set connect_now=False on initialization.

If some connections have failed to connect successfully or provide box.info status (including the case when all of them have failed), no exceptions are raised. Attempts to reconnect and refresh the info would be processed in the background.

crud_count(space_name, conditions=None, opts=None, *, mode=Mode.ANY)¶

Execute an crud_count request on the pool server: gets rows count through the crud. Refer to crud_count().

Parameters

space_name¶ – Refer to space_name.
conditions¶ – Refer to conditions.
opts¶ – Refer to opts.
mode¶ (Mode, optional) – Request mode.

Return type

module tarantool.connection_pool¶

module `tarantool.connection_pool`¶