Reference to Request: REQ518678,DD-1316


**Changelog: Improved Fault Tolerance for Queue Failures and Version Checks**

**Affected Areas**:

* `payment` subsystem
* `Kundenstamm` subsystem
* `single`, `batch` subsystems

---

 **Before Patch**

* **payment / Kundenstamm**:

  * In case of queue failures, services were immediately restarted.
  * If there were 10 consecutive failures when requesting the current list version, the system triggered a service restart.

* **single / batch**:

  * Similarly, if 10 consecutive failures occurred when requesting the current list version, the system restarted the service.

---

 **After Patch**

* **payment / Kundenstamm**:

  * On queue failure, the system now attempts to **recover the connection automatically** up to **10 times**, with **increasing retry intervals**.

    * If reconnection is successful, the service **continues processing** without restart.
    * If reconnection fails after all attempts, a **restart is triggered**.
  * The **wait time before issuing a restart command** has been reduced.
  * When requesting the current list version:

    * A successfully retrieved version is **cached**.
    * If up to 10 retries fail, the system **returns the cached version** instead of failing or restarting.

* **single / batch**:

  * When requesting the current list version:

    * A successful version fetch is **cached**.
    * If 10 consecutive failures occur, the **cached version is returned**.




