This page provides information for self-managed customers configuring the data service. The data service configuration is specified in
data-server-cluster element in the
appian-topology.xml file, located in both the
1 2 3 4 5 6 <topology> ... <data-server-cluster> <data-server host="machine1.example.com" port="5400" rts-count="2"/> </data-server-cluster> </topology>
For a high availability configuration, specify three instances of the data service on different machines:
1 2 3 4 5 6 7 8 <topology> ... <data-server-cluster> <data-server host="machine1.example.com" port="5400" rts-count="2"/> <data-server host="machine2.example.com" port="5400" rts-count="2"/> <data-server host="machine3.example.com" port="5400" rts-count="2"/> </data-server-cluster> </topology>
You must specify the
data-server-cluster configuration in
appian-topology.xml. Copy the
appian-topology.xml file from
<APPIAN_HOME>/data-server/conf/ before starting the data service. Copies of the topology file in each location must always be in sync, irrespective of the configurations specified.
data-server node element must be present and must be structured similarly to the following:
1 <data-server host="machine3.example.com" port="5400" rts-count="2"/>
If there is no
data-server node element specified, the following error is printed in
"ERROR com.appian.data.server.Watchdog - At least one data-server node must be specified"
host attribute in the
data-server element to the name of the machine hosting the data service. If the
host is not specified, the following error is printed in
"ERROR com.appian.data.server.Watchdog - data-server host must be specified"
You can define the
port attribute on both the
data-server-cluster and the
data-server elements. If the
port attribute is defined on both, the
data-server element takes precedence. If not supplied, the default port number is
In order for the data service to function properly, make sure that you open all of the required ports. See Port Usage for more information.
rts-count attribute specifies the number of real-time stores in the data service. The real-time store component is responsible for processing queries to the data service, and each real-time store processes a single query at a time.
For self-managed customers, the
rts-count is set to 2 by default, but can be increased as needed to support increased query throughput. The maximum supported
rts-count varies based on the amount of memory available as shown below.
|Available Memory||Supported RTS Count|
|Less than 32GB||2|
|Between 32GB - 127GB||4|
|Between 128GB - 384GB||8|
|Greater than or equal to 384GB||12|
Topology changes can include:
To make these changes, you'll need to make configuration changes to the
data-server-cluster parameter and restart both the data service and the application server by following these steps:
<APPIAN_HOME>/ae/data-server/node/electiondirectory from all the servers. This directory contains runtime data that needs to be deleted when certain topology changes are made.
<APPIAN_HOME>/ae/data-server/datadirectory to the new servers.
Configuring the Data Service