Are the query methods for process instance available on CamundaClient

Camunda 8 Topics
,
1

(Camunda 8 Run, running on Windows)

Are these methods of the CamundaClient fully operational?

client.newProcessInstanceSearchRequest().send()

client.newProcessInstanceGetRequest(…).send()

The first one does not return anything and the second returns an exception.

io.camunda.client.api.command.MalformedResponseException: Expected to receive a problem body, but got an actual response: class ProcessInstanceResult {
    processDefinitionId: null
    processDefinitionName: null
    processDefinitionVersion: null
    processDefinitionVersionTag: null
    startDate: null
    endDate: null
    state: null
    hasIncident: null
    tenantId: null
    processInstanceKey: null
    processDefinitionKey: null
    parentProcessInstanceKey: null
    parentElementInstanceKey: null
    tags: []
}
	at io.camunda.client.impl.http.ApiCallback.handleErrorResponse(ApiCallback.java:116)
	at io.camunda.client.impl.http.ApiCallback.completed(ApiCallback.java:72)
	at io.camunda.client.impl.http.ApiCallback.completed(ApiCallback.java:32)
	at org.apache.hc.core5.concurrent.BasicFuture.completed(BasicFuture.java:148)
	at org.apache.hc.core5.concurrent.ComplexFuture.completed(ComplexFuture.java:72)
	at org.apache.hc.client5.http.impl.async.InternalAbstractHttpAsyncClient$2$1.completed(InternalAbstractHttpAsyncClient.java:321)
	at org.apache.hc.core5.http.nio.support.AbstractAsyncResponseConsumer$1.completed(AbstractAsyncResponseConsumer.java:101)
	at org.apache.hc.core5.http.nio.entity.AbstractBinAsyncEntityConsumer.completed(AbstractBinAsyncEntityConsumer.java:87)
	at org.apache.hc.core5.http.nio.entity.AbstractBinDataConsumer.streamEnd(AbstractBinDataConsumer.java:83)
	at org.apache.hc.core5.http.nio.support.AbstractAsyncResponseConsumer.streamEnd(AbstractAsyncResponseConsumer.java:142)
	at org.apache.hc.client5.http.impl.async.HttpAsyncMainClientExec$1.streamEnd(HttpAsyncMainClientExec.java:283)
	at org.apache.hc.core5.http.impl.nio.ClientHttp1StreamHandler.dataEnd(ClientHttp1StreamHandler.java:285)
	at org.apache.hc.core5.http.impl.nio.ClientHttp1StreamDuplexer.dataEnd(ClientHttp1StreamDuplexer.java:371)
	at org.apache.hc.core5.http.impl.nio.AbstractHttp1StreamDuplexer.onInput(AbstractHttp1StreamDuplexer.java:340)
	at org.apache.hc.core5.http.impl.nio.AbstractHttp1IOEventHandler.inputReady(AbstractHttp1IOEventHandler.java:64)
	at org.apache.hc.core5.http.impl.nio.ClientHttp1IOEventHandler.inputReady(ClientHttp1IOEventHandler.java:41)
	at org.apache.hc.core5.reactor.InternalDataChannel.onIOEvent(InternalDataChannel.java:143)
	at org.apache.hc.core5.reactor.InternalChannel.handleIOEvent(InternalChannel.java:51)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.processEvents(SingleCoreIOReactor.java:176)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.doExecute(SingleCoreIOReactor.java:125)
	at org.apache.hc.core5.reactor.AbstractSingleCoreIOReactor.execute(AbstractSingleCoreIOReactor.java:92)
	at org.apache.hc.core5.reactor.IOReactorWorker.run(IOReactorWorker.java:44)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Looking at the Examples at GitHub we don’t see any with instance queries, so I’m wondering if this bit is not yet available yet.

PS. ZeebClient didn’t work for me either either.

2

Works fine with Camunda Run 8.8.

3

Hi @claudio_rio,

Based on your question, I can classify this as a Problem - the methods you’re trying to use are not behaving as expected.

The short answer is: These methods are not fully operational in Camunda 8.7, and this is expected behavior.

Current Status of Process Instance Query Methods

The newProcessInstanceSearchRequest() and newProcessInstanceGetRequest() methods you’re trying to use are part of the alpha Query API in Camunda 8.7. Here’s what’s happening:

1. Alpha Feature Status

  • These process instance query endpoints are alpha features in Camunda 8.7
  • They are not fully stable or enabled by default
  • You must explicitly enable the Query API with CAMUNDA_REST_QUERY_ENABLED=true
  • Even when enabled, you may encounter limitations and issues

2. The MalformedResponseException

The exception you’re seeing suggests a response structure mismatch. This can happen because:

  • The client expects certain response fields that the server doesn’t provide
  • There may be API version mismatches (client using v2 endpoints while server exposes v1)
  • The alpha API implementation is not fully stable

3. Client Transition Period

In Camunda 8.7, there’s an ongoing transition from the Zeebe Java client to the unified CamundaClient. The process instance query functionality is limited and not fully implemented yet.

Recommendations

For Camunda 8.7:

  1. Use the Operate API instead for process instance queries:

    // Use Operate API for reliable process instance queries
// See: https://docs.camunda.io/docs/apis-tools/operate-api/

  2. Enable Query API (if you want to experiment with alpha features):

    CAMUNDA_REST_QUERY_ENABLED=true

For Production Use:

Upgrade to Camunda 8.8 or later where:

  • The CamundaClient becomes the official unified Java client
  • Process instance query methods are expected to be stable and fully available
  • Use the new io.camunda:camunda-client-java artifact

Alternative Solutions

Until you can upgrade, consider:

The lack of examples in the GitHub repository you mentioned confirms that these features are not yet ready for general use in 8.7.

References:

Hope this clarifies the current status! Let me know if you need help with alternative approaches or have questions about upgrading.

4

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.