Cisco Common Data Layer

Feature Summary and Revision History

Summary Data

Table 1. Summary Data

Applicable Product(s) or Functional Area

SMF

Applicable Platform(s)

SMI

Feature Default Setting

Disabled – Configuration Required

Related Changes in this Release

Not Applicable

Related Documentation

Not Applicable

Revision History

Table 2. Revision History

Revision Details

Release

First introduced.

Pre-2020.02.0

Feature Description

The PCF extends support to the Geo Redundant (GR) version of the Cisco Common Data Layer (CDL). When the primary CDL endpoint fails, PCF attempts the same operation on the next highly rated secondary endpoint thus providing a non-disrupted N7 or Diameter message handling. If the next rated endpoint is unavailable, then PCF reattempts the operation on the subsequent endpoint that has the highest rating and so on.

Architecture

The following figure depicts the failover that happens when the SMF service is unable to access the CDL datastore endpoint.

Figure 1. CDL Datastore Architecture

With relevance to this architecture, you can configure CDL through SMF Ops Center. When the SMF connects to the CDL, it uses the local endpoints.

How it Works

When you configure the CDL in SMF through the SMF Ops Center, SMF gets enabled to support multiple CDL datastore endpoints. You can configure the endpoints by specifying the IP addresses, ports, and assigning ratings to each endpoint. By default, SMF considers the local endpoint as the primary endpoint, which has the highest rating. SMF performs CDL API operations on the primary endpoint. If this endpoint is unavailable, then SMF routes the operations to the next highest rated endpoint. SMF keeps failing over to the accessible secondary endpoint or until all the configured secondaries are exhausted. It does not reattempt a query on the next rated endpoint if the endpoint is reachable but responds with error or timeout.

If SMF is unable to access any of the endpoints in the cluster, then CDL operation fails with the "Datastore Unavailable" error.

Call Flows

This section describes the call flow that is associated with this feature.

CDL Endpoint Failure Call Flow

This section describes the SMF local data store endpoint failure call flow.

Figure 2. CDL Endpoint Failure Call Flow
Table 3. CDL Endpoint Failure Call Flow Description
Step Description

1

The AMF sends a Create Request to SMF REST endpoint over the N11 interface.

2

After receiving the request, the SMF REST endpoint forwards the Create Request to the SMF service.

3

The SMF service attempts to reach the CDL endpoint to send the session creation request. However, the CDL endpoint is unreachable.

4

The Create Request is evaluated in the stored session and the SMF service forwards the request to the CDL endpoint.

5

After the call request is successful, the SMF service notifies the Success Message to the SMF REST endpoint.

6

The SMF REST endpoint forwards the Success Message to the AMF.

Limitations

The CDL configuration in SMF has the following limitations:

  • The SMF service attempts to reroute the calls only when it encounters gRPC errors such as UNAVAILABLE. It does not acknowledge errors that the datastore endpoint returns and actual gRPC timeouts such as DEADLINE_EXCEEDED gRPC status code.

  • The SMF service does not resolve failures occurring with the datastore such as indexing and slot failures. The CDL layer must resolve these failures and if necessary, send an API call on the remote.

Configuring the CDL Through SMF Ops Center

The configuration of the CDL using SMF Ops Center involves the following steps:

  1. Configuring the CDL Session Database and Defining the Base Configuration

  2. Configuring the Zookeeper in CDL

Configuring the CDL Session Database and Defining the Base Configuration

This section describes how to configure the CDL session database and define the base configuration in SMF.

  1. From the SMF Ops Center, run the following command to configure the CDL session database and base configuration.

    configure 
   cdl system-id  system_id 
   cdl node-type  node_type 
   cdl zookeeper replica  zookeeper_replica_id 
   exit  
   cdl logging default-log-level  debug_level 
      cdl datastore session  
      cluster-id  cluster_id 
      endpoint replica  1 
      endpoint replica  num_replica 
         index map  map_value 
         slot replica  num_replica 
         slot map  num_map/shards 
         slot write-factor  write_factor 
         slot notification host  host 
         slot notification port  port 
         slot notification limit  tps 
         index replica  num_replica 
         index map  num_map/shards 
         index write-factor   write_factor 
         end

NOTES:

  • cdl system-id system_id : This is an optional command. Specifies the system or Kubernetes cluster identity. The default value is 1.

  • cdl node-type node_type : This is an optional command. Specifies the Kubernetes node label to configure the node affinity. The default value is “session.” Accepted length of the value is 0–64 alphabets.

  • cdl zookeeper replica zookeeper_replica_id : Specifies the zookeeper replica server's ID.

  • endpoint replica num_replica : This is an optional command. Specifies the number of replicas to be created. The default value is 1. Must be an integer in the range of 1–16.

  • slot replica num_replica : This is an optional command. Specifies the number of replicas to be created. The default value is 1. num_replica must be an integer in the range of 1–16.

  • slot map num_map/shards : This is an optional command. Specifies the number of partitions in a slot. The default value is 1. num_map/shards must be an integer in the range of 1–1024.

  • slot write-factor write_factor : This is an optional command. Specifies the number of copies to be written before successful response. The default value is 1. write_factor must be an integer in the range of 0–16. Make sure that the value is lower than or equal to the number of replicas.

  • slot notification host host : This is an optional command. Specifies the notification server hostname or IP address. The default value is datastore-notification-ep.

  • slot notification port port : This is an optional command. Specifies the notification server Port number. The default value is 8890.

  • slot notification limit tps : This is an optional command. Specifies the notification limit per second. The default value is 2000.

  • index replica num_replica : This is an optional command. Specifies the number of replicas to be created. The default value is 2. num_replica must be an integer in the range of 1–16.

  • index map num_map/shards : This is an optional command. Specifies the number of partitions in a slot. The default value is 1. num_map/shards must be an integer in the range of 1–1024. Avoid modifying this value after deploying the CDL.

  • index write-factor write_factor : This is an optional command. Specifies the number of copies to be written before successful response. The default value is 1. write_factor must be an integer in the range of 0–16.

Configuring the Zookeeper in CDL

This section describes how to configure the Zookeeper in CDL.

  1. Open the Policy Ops Center console and navigate to the datastore CLI.

  2. Run the following command to define the parameters.

    
configure 
   cdl zookeeper data-storage-size data_storage_size_in_gb 
      log-storage-size log_storage_size_in_gb 
      replica number_of_replicas 
      enable-JMX-metrics boolean_value 
      enable-persistence boolean_value 
      end

    NOTES:

    All the following parameters are optional.

    • cdl zookeeper data-storage-size data_storage_size_in_gb : Specifies the size of the Zookeeper data storage in gigabyte. The default value is 20 GB. Accepted value is an integer in the range of 1-64.

    • log-storage-size log_storage_size_in_gb : Specifies the size of the Zookeeper data log's storage in gigabyte. The default value is 20 GB. Accepted value is an integer in the range of 1-64.

    • replica num_replicas : Specifies the number of replicas that must be created. The default value is 3. Accepted value is an integer in the range of one to 16.

    • enable-JMX-metrics boolean_value : Specifies the status of the JMX metrics. The default value is true.

    • enable-persistence boolean_value : Specifies the status of the persistent storage for Zookeeper data. The default value is false .

Sample Configuration

This section shows a sample configuration of CDL in a HA environment.

cdl system-id system_id
cdl zookeeper replica num_zk_replica
cdl datastore session
 endpoint replica ep_replica
index map index_shard_count
 slot replica slot_replica
 slot map slot_shard_count
exit