Table Data Cache Proxy runbook

The Table Data Cache Proxy (TDCP) is a Deephaven data management service that caches table data to reduce load on upstream data servers. It multiplexes data requests from multiple local worker processes to minimize connections to high-traffic sources like the Data Import Server (DIS).

Impact of Table Data Cache Proxy failure

LevelImpact
Sev 1 - CriticalIntraday data will not be available to workers on this host. Workers will fail to start or will be unable to access table data, causing query failures.

Note

TDCP is typically deployed on every host with workers. Its failure affects only the workers on that host, not the entire cluster.

Table Data Cache Proxy dependencies

The TDCP requires:

  1. Configuration Server — Must be running to access routing configuration.
  2. Authentication Server — Must be running for token validation.
  3. Upstream data servers — DIS, LTDS, or other TDCP instances must be accessible.
  4. etcd cluster — Must be accessible (via Configuration Server).

Checking Table Data Cache Proxy status

Check process is running with monit:

Expected output should show status Running.

Viewing Table Data Cache Proxy logs

View application log:

Tail the log to follow in real-time:

List historical log files:

View process stdout/stderr logs:

Restart procedure

Restart the TDCP:

Warning

Restarting the TDCP disconnects all active worker connections and clears the in-memory cache. Workers automatically reconnect and resume subscriptions, but there may be a brief interruption in data access.

Verify the restart was successful:

Monitor the log during startup:

Routing configuration

The TDCP uses the routing configuration to determine how to route table requests to upstream data servers. Routing is managed through dhconfig routing and can be updated dynamically without restarting the TDCP.

See Data routing overview and dhconfig routing command reference for details.

Configuration files and locations

monit configuration: /etc/sysconfig/illumon.d/monit/db_tdcp.conf

Property files:

  • /etc/sysconfig/illumon.d/resources/iris-common.prop
  • Service-specific properties configured through dhconfig

Routing configuration: Managed through dhconfig routing

Log directory: /var/log/deephaven/tdcp/