кому интересно, нам помогли следующие настройки <job-executor>
<job-acquisition name="default">
<properties>
<!-- Sets the maximal number of jobs to be acquired at once. -->
<property name="maxJobsPerAcquisition">3</property>
<!-- Specifies the wait time of the job acquisition thread in milliseconds in case there are less jobs available for execution than requested during acquisition. -->
<!-- If this is repeatedly the case, the wait time is increased exponentially by the factor waitIncreaseFactor. The wait time is capped by 'maxWait'. -->
<property name="waitTimeInMillis">5000</property>
<!-- Specifies the time in milliseconds an acquired job is locked for execution. During that time, no other job executor can acquire the job. -->
<property name="lockTimeInMillis">300000</property>
<!-- Specifies the maximum wait time of the job acquisition thread in milliseconds in case there are less jobs available for execution than requested during acquisition. -->
<property name="maxWait">60000</property>
</properties>
</job-acquisition>
<properties>
<!-- Sets the size of the queue which is used for holding tasks to be executed. -->
<!-- Overrides by environment variable: CAMUNDA_EXECUTOR_QUEUESIZE -->
<property name="queueSize">3</property>
<!-- Sets the size of the core pool in the thread pool. This number of threads will always be present and wait to execute tasks. -->
<!-- Overrides by environment variable: CAMUNDA_EXECUTOR_COREPOOLSIZE -->
<property name="corePoolSize">3</property>
<!-- Sets the maximum number of threads that can be present in the thread pool. -->
<!-- Overrides by environment variable: CAMUNDA_EXECUTOR_MAXPOOLSIZE -->
<property name="maxPoolSize">10</property>
</properties>
</job-executor>