transport

class opensearchpy.Transport(hosts, connection_class=None, connection_pool_class=<class 'opensearchpy.connection_pool.ConnectionPool'>, host_info_callback=<function get_host_info>, sniff_on_start=False, sniffer_timeout=None, sniff_timeout=0.1, sniff_on_connection_fail=False, serializer=<opensearchpy.serializer.JSONSerializer object>, serializers=None, default_mimetype='application/json', max_retries=3, pool_maxsize=None, retry_on_status=(502, 503, 504), retry_on_timeout=False, send_get_body_as='GET', metrics=<opensearchpy.metrics.metrics_none.MetricsNone object>, **kwargs)

Bases: object

Encapsulation of transport-related to logic. Handles instantiation of the individual connections as well as creating a connection pool to hold them.

Main interface is the perform_request method.

Parameters:

• hosts (Any) – list of dictionaries, each containing keyword arguments to create a connection_class instance

• connection_class (Type[Connection]) – subclass of Connection to use

• connection_pool_class (Any) – subclass of ConnectionPool to use

• host_info_callback (Any) – callback responsible for taking the node information from /_cluster/nodes, along with already extracted information, and producing a list of arguments (same as hosts parameter)

• sniff_on_start (bool) – flag indicating whether to obtain a list of nodes from the cluster at startup time

• sniffer_timeout (float | None) – number of seconds between automatic sniffs

• sniff_on_connection_fail (bool) – flag controlling if connection failure triggers a sniff

• sniff_timeout (float | None) – timeout used for the sniff request - it should be a fast api call and we are talking potentially to more nodes so we want to fail quickly. Not used during initial sniffing (if sniff_on_start is on) when the connection still isn’t initialized.

• serializer (Serializer) – serializer instance

• serializers (Mapping[str, Serializer] | None) – optional dict of serializer instances that will be used for deserializing data coming from the server. (key is the mimetype)

• default_mimetype (str) – when no mimetype is specified by the server response assume this mimetype, defaults to ‘application/json’

• max_retries (int) – maximum number of retries before an exception is propagated

• retry_on_status (Collection[int]) – set of HTTP status codes on which we should retry on a different node. defaults to (502, 503, 504)

• retry_on_timeout (bool) – should timeout trigger a retry on different node? (default False)

• send_get_body_as (str) – for GET requests with body this option allows you to specify an alternate way of execution for environments that don’t support passing bodies with GET requests. If you set this to ‘POST’ a POST method will be used instead, if to ‘source’ then the body will be serialized and passed as a query parameter source.

• pool_maxsize (int | None) – Maximum connection pool size used by pool-manager For custom connection-pooling on current session

• metrics (Metrics) – metrics is an instance of a subclass of the Metrics class, used for collecting and reporting metrics related to the client’s operations;

• hosts –

• connection_class –

• connection_pool_class –

• host_info_callback –

• sniff_on_start –

• sniffer_timeout –

• sniff_timeout –

• sniff_on_connection_fail –

• serializer –

• serializers –

• default_mimetype –

• max_retries –

• pool_maxsize –

• retry_on_status –

• retry_on_timeout –

• send_get_body_as –

• metrics –

• kwargs (Any) –

Any extra keyword arguments will be passed to the connection_class when creating and instance unless overridden by that connection’s options provided as part of the hosts parameter.

DEFAULT_CONNECTION_CLASS

alias of Urllib3HttpConnection

_get_sniff_data(initial=False)

Perform the request to get sniffing information. Returns a list of dictionaries (one per node) containing all the information from the cluster.

It also sets the last_sniff attribute in case of a successful attempt.

In rare cases it might be possible to override this method in your custom Transport class to serve data from alternative source like configuration management.

Parameters:

initial (bool) –

Return type:

Any

_resolve_request_args(method, params, body)

Resolves parameters for .perform_request()

Parameters:

• method (str) –

• params (Any) –

• body (Any) –

Return type:

Any

add_connection(host)

Create a new Connection instance and add it to the pool.

Parameters:

• host (Any) – kwargs that will be used to create the instance

• host –

Return type:

None

close()

Explicitly closes connections

Return type:

Any

get_connection()

Retrieve a Connection instance from the ConnectionPool instance.

Return type:

Any

mark_dead(connection)

Mark a connection as dead (failed) in the connection pool. If sniffing on failure is enabled this will initiate the sniffing process.

Parameters:

• connection (Connection) – instance of Connection that failed

• connection –

Return type:

None

perform_request(method, url, params=None, body=None, timeout=None, ignore=(), headers=None)

Perform the actual request. Retrieve a connection from the connection pool, pass all the information to its perform_request method and return the data.

If an exception was raised, mark the connection as failed and retry (up to max_retries times).

If the operation was successful and the connection used was previously marked as dead, mark it as live, resetting its failure count.

Parameters:

• method (str) – HTTP method to use

• url (str) – absolute url (without host) to target

• headers (Mapping[str, str] | None) – dictionary of headers, will be handed over to the underlying Connection class

• params (Mapping[str, Any] | None) – dictionary of query parameters, will be handed over to the underlying Connection class for serialization

• body (Any | None) – body of the request, will be serialized using serializer and passed to the connection

• method –

• url –

• params –

• body –

• timeout (int | float | None) –

• ignore (Collection[int]) –

• headers –

Return type:

Any

set_connections(hosts)

Instantiate all the connections and create new connection pool to hold them. Tries to identify unchanged hosts and re-use existing Connection instances.

Parameters:

• hosts (Any) – same as __init__

• hosts –

Return type:

None

sniff_hosts(initial=False)

Obtain a list of nodes from the cluster and create a new connection pool using the information retrieved.

To extract the node connection parameters use the nodes_to_host_callback.

Parameters:

• initial (bool) – flag indicating if this is during startup (sniff_on_start), ignore the sniff_timeout if True

• initial –

Return type:

Any