Local Table Data Server runbook

The Local Table Data Server (LTDS) is an optional Deephaven process (db_ltds) that serves intraday table data from the local filesystem over the table data service (TDS) protocol. It is no longer started as part of the default installation, but remains available for deployments that need to publish local data as a network service or offload read traffic from other table data providers.

Impact of Local Table Data Server failure

LevelImpact
Sev 2 - ModerateIf the LTDS is configured in the routing, then any data it serves will not be available. Intraday data served by this LTDS will be inaccessible until the service is restored.

Note

LTDS is optional. If not configured in routing, its failure has no impact. The severity depends on how critical the data it serves is to operations.

Local Table Data Server dependencies

The LTDS requires:

  1. Configuration Server — Must be running to access table schemas and routing.
  2. Authentication Server — Must be running for token validation.
  3. Filesystem access — Must have read access to data storage paths.
  4. etcd cluster — Must be accessible (via Configuration Server).

The LTDS does not depend on:

  • Data Import Server
  • Data tailers
  • Write processes

Checking Local Table Data Server status

Check process is running with monit:

Expected output should show status Running.

Viewing Local Table Data Server 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 LTDS:

Impact: Restarting LTDS will disconnect all clients reading data from this server. Clients will need to reconnect (often automatic via routing) and re-subscribe to tables.

Verify the restart was successful:

Monitor the log during startup:

Routing configuration

LTDS loads its routing configuration from the tableDataServices section of the routing YAML. See Table data services configuration for configuration details and dhconfig routing command reference for importing and exporting routing configuration.

Configuration files and locations

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

Property files:

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

Data directory: Configured per routing — LTDS serves intraday data from /db/Intraday/<namespace>/<tableName> on the local host

Log directory: /var/log/deephaven/ltds/