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Gyeeta Server Components Failover / Redundancy

Gyeeta supports Failover Handling (High Availability) for its Server components :

  • Shyama Central Server (Active-Passive mode)

  • Madhava Intermediate Servers (Active-Passive mode)

  • Node Webservers (Active-Active mode)

  • Alert Action Agent (Active-Active mode)

For Postgres DB Failover, we recommend using a Shared Disk Failover or setting up Logical Replication (which is disabled by default).

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This section can be ignored for Kubernetes based Gyeeta Installs.

It is recommended that the failover installs be done on a separate host as compared to the Active installation for better Redundancy.

Shyama Server Redundancy​

Shyama Server Redundancy is provided by sharing the Postgres DB amongst the Active-Passive Shyama instances.

For this, all the Active-Passive Shyama instances will need to have some of the Config Options shared across all instances. Namely, the following Config fields need to be same across the Active-Passive Shyama instances :

  • shyama_name json field or CFG_SHYAMA_NAME env
  • shyama_secret json field or CFG_SHYAMA_SECRET env
  • min_madhava json field or CFG_MIN_MADHAVA env
  • postgres_hostname json field or CFG_POSTGRES_HOSTNAME env
  • postgres_port json field or CFG_POSTGRES_PORT env
  • postgres_user json field or CFG_POSTGRES_USER env
  • postgres_password json field or CFG_POSTGRES_PASSWORD env

In addition to the config fields above, any CLI arguments passed to all Shyama Instances needs to be same for all instances.

The Passive Shyama instances will monitor the Active Shyama status and on detecting a Failure condition, one of the Passive Shyama instances will then take over as the next Active Instance.

The Failover can take upto 3 minutes time duration.

Madhava Server Redundancy​

Madhava Server Redundancy is provided by sharing the Postgres DB amongst the Active-Passive Madhava instances.

For this, all the Active-Passive Madhava instances will need to have some of the Config Options shared across all instances. Namely, the following Config fields need to be same across the Active-Passive Madhava instances :

  • shyama_hosts json field or CFG_SHYAMA_HOSTS env
  • shyama_ports json field or CFG_SHYAMA_PORTS env
  • shyama_secret json field or CFG_SHYAMA_SECRET env
  • madhava_name json field or CFG_MADHAVA_NAME env
  • postgres_hostname json field or CFG_POSTGRES_HOSTNAME env
  • postgres_port json field or CFG_POSTGRES_PORT env
  • postgres_user json field or CFG_POSTGRES_USER env
  • postgres_password json field or CFG_POSTGRES_PASSWORD env

The Passive Madhava instances will monitor the Active Madhava status and on detecting a Failure condition, one of the Passive Madhava instances will then take over as the next Active Instance.

The Failover can take upto 3 minutes time duration.

Node Webserver Redundancy​

Node Webserver Redundancy can be provided by installing multiple instances of the Webserver in an Active-Active mode.

For this, all the Active-Active Webserver instances will need to have some of the Config Options shared across all instances.

  • CFG_SHYAMA_HOSTS
  • CFG_SHYAMA_PORTS
  • CFG_ADMINPASSWORD
  • CFG_USERPASSFILE
  • CFG_TOKENEXPIRY
  • CFG_JWTSECRET
  • CFG_USEHTTP
  • CFG_TLSCERTFILE
  • CFG_TLSKEYFILE
  • CFG_TLSPASSPHRASE

As the Webserver instances are running in Active-Active mode, users can connect to any of the Webserver instances to access the Web UI or use for REST APIs.

tip

Although any of the Webserver instances can be used for querying, it is recommended that users query from a single Webserver instance for better querying performance as Resultset caching is not shared across Webserver instances.

Alert Agent Redundancy​

Alert Agent Redundancy can be provided by installing multiple instances of the Alert Agent in an Active-Active mode.

For this, all the Active-Active Webserver instances will need to have some of the Config Options shared across all instances.

  • CFG_SHYAMA_HOSTS
  • CFG_SHYAMA_PORTS

As the Alert Agent instances are running in Active-Active mode, the Shyama server will assign any of the Alert Agents the Notification responsibilities.