.. _cartridge.topology:

===============================================================================
Module *cartridge.topology*
===============================================================================

Topology validation and filtering.




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Functions
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.. _cartridge.topology.cluster_is_healthy:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cluster_is_healthy ()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Check the cluster health. 
It is healthy if all instances are healthy.

The function is designed mostly for testing purposes.




**Returns**:

(**boolean**) true / false


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Local Functions
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.. _cartridge.topology.get_leaders_orded:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
get_leaders_orded (topology_cfg, replicaset_uuid, new_order)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Get full list of replicaset leaders. 

Full list is composed of:

* New order array
* Initial order from topology_cfg (with no repetitions)
* All other servers in the replicaset, sorted by uuid, ascending


Neither  ``topology_cfg``  nor  ``new_order``  tables are modified.
New order validity is ignored too.



**Parameters:**

- *topology_cfg:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   
- *replicaset_uuid:* (`string <https://www.lua.org/manual/5.1/manual.html#5.4>`_)   
- *new_order:* (optional `table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   

**Returns**:

(`{string,...} <https://www.lua.org/manual/5.1/manual.html#5.4>`_) array of leaders uuids


.. _cartridge.topology.validate:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
validate (topology_new, topology_old)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Validate topology configuration.


**Parameters:**

- *topology_new:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   
- *topology_old:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   

**Returns**:

(**boolean**) true


**Or**

(**nil**) 

(`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_) Error description


.. _cartridge.topology.find_server_by_uri:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
find_server_by_uri (topology_cfg, uri)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Find the server in topology config. 

(**Added** in v1.2.0-17)



**Parameters:**

- *topology_cfg:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   
- *uri:* (`string <https://www.lua.org/manual/5.1/manual.html#5.4>`_)   

**Returns**:

(**nil** or `string <https://www.lua.org/manual/5.1/manual.html#5.4>`_) `instance_uuid` found


.. _cartridge.topology.refine_servers_uri:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
refine_servers_uri (topology_cfg)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Merge servers URIs form topology_cfg with fresh membership status. 

This function sustains cartridge operability in case of
advertise_uri change. The uri map is composed basing on
topology_cfg, but if some of them turns out to be dead, the
member with corresponding payload.uuid is searched beyond.

(**Added** in v2.3.0-7)



**Parameters:**

- *topology_cfg:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   

**Returns**:

(**{[uuid]**) = uri} with all servers except expelled ones.


.. _cartridge.topology.probe_missing_members:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
probe_missing_members (servers)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Send UDP ping to servers missing from membership table.


**Parameters:**

- *servers:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   

**Returns**:

(**boolean**) true


**Or**

(**nil**) 

(`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_) Error description


.. _cartridge.topology.get_fullmesh_replication:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
get_fullmesh_replication (topology_cfg, replicaset_uuid)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Get replication config to set up full mesh. 

(**Added** in v1.2.0-17)



**Parameters:**

- *topology_cfg:* (`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_)   
- *replicaset_uuid:* (`string <https://www.lua.org/manual/5.1/manual.html#5.4>`_)   

**Returns**:

(`table <https://www.lua.org/manual/5.1/manual.html#5.5>`_) 


