Strategy: Single Engine - Multiple apps deploy bpmn flows

Camunda 7 Topics Discussion & Questions
1

Our clients(or users or apps) would build workflows; maintain bmpn files; but wish to deploy into one central custom common engine. There could be multiple such clients; each deploying and executing serveral flows independently.
What should be our strategy.:

  1. REST Endpoints only; Deployed, executed, monitor all through APIs exposed by this engine.
  2. Build a small JDK like jar and share with clients to provide a more easy-to-use feature.
  3. Can every client builds a jar of its bpmn files and its custom delegates; with its own processes xml(Process Application); so multiple processes xml are hosted in single engine. Is this possible?
    Any other better approaches, best practices. Please suggest.
2

You can’t have multiple processes.xml files for one camunda distribution deployment.

But you can configure multiple process engines in the processes.xml or setup a one process engine which can be shared with all the clients.

You should go through this for multi-tenancy setup: Multi-Tenancy | docs.camunda.org

Approach 1: One Process Engine Per Tenant

  • Multi-Tenancy can be achieved by providing one process engine per tenant.
  • Each process engine is configured to use a different data source which connects the data of the tenant.
  • The data of the tenants can be stored in different databases, in one database with different schemas or in one schema with different tables.

Approach 2: Single Process Engine With Tenant-Identifiers

  • Multi-Tenancy can be achieved with one process engine which uses tenant identifiers (i.e., tenant-ids).
  • The data of all tenants is stored in one table (same database and schema).
  • Isolation is provided by the means of a tenant identifier that is stored in a column.

Multiple process engines can be configured like this:

<process-application
  xmlns="http://www.camunda.org/schema/1.0/ProcessApplication"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <process-archive name="tenant1-archive">
    <process-engine>tenant1</process-engine>
    <properties>
      <property name="resourceRootPath">classpath:processes/tenant1/</property>
      <property name="isDeleteUponUndeploy">false</property>
      <property name="isScanForProcessDefinitions">true</property>
    </properties>
  </process-archive>

  <process-archive name="tenant2-archive">
    <process-engine>tenant2</process-engine>
    <properties>
      <property name="resourceRootPath">classpath:processes/tenant2/</property>
      <property name="isDeleteUponUndeploy">false</property>
      <property name="isScanForProcessDefinitions">true</property>
    </properties>
  </process-archive>

</process-application>
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