# Amazon EMR 7.1.0 - Tez release notes
<a name="Tez-release-history-710"></a>

## Amazon EMR 7.1.0 - Tez changes
<a name="Tez-release-history-changes-710"></a>


| Type | Description | 
| --- | --- | 
| Bug Fix | [TEZ-4394](https://issues.apache.org/jira/browse/TEZ-4394) – Netty4 ShuffleHandler: should use 1 boss thread (\$1256)  | 
| Upgrade | Upgrades Netty to 4.1.100.Final. | 
| Upgrade | Upgrades Jetty to 9.4.53.v20231009. | 

**Amazon EMR 7.1.0 - Tez known issues**
+ **Tez DAG cleanup issue (EMR 6.11.0 - EMR 7.2.0)** – In clusters with SSL enabled running EMR versions 6.11.0 to 7.2.0, there is a known issue where *SSLHandshakeException* occurs in TEZ Application Master (AM) during the DAG cleanup phase. This happens when attempting to delete intermediate shuffle data from remote nodes over HTTPS after query completion, not during the query execution. The issue occurs because Tez AM cannot read the relevant **trustStore** configuration when calling the shuffle handler service endpoint. However this affects only the cleaning up of shuffle data during DAG cleanup, the application(AM) level cleanup happens anyways and cleans up any lingering shuffle data. So this doesn’t lead to shuffle data accumulation. 

  **Fix version:** – EMR 7.3.0

  **Workaround** – Add the following SSL configuration to tez-site.xml:

  ```
  <property>
      <name>ssl.client.truststore.location</name>
      <value>{SSL_TRUSTSTORE_LOCATION}</value>
  </property>
  ```
+ **Pig jobs running on Tez** – In clusters with SSL enabled running EMR version 6.9.0 to 7.0.0, there is a known issue where Pig jobs running on Tez fail with *SSLHandshakeException*. This is related to the open-source issue [TEZ-4096](https://issues.apache.org/jira/browse/TEZ-4096), which was introduced with the Tez upgrade to version 0.10.2 in EMR 6.9.0. The issue requires SSL-related configurations to be passed from the client side (Pig).

  **Fix version:** – EMR 7.1.0

  **Workaround** – Add the following SSL configuration to tez-site.xml:

  ```
  <property>
      <name>ssl.client.truststore.location</name>
      <value>{SSL_TRUSTSTORE_LOCATION}</value>
  </property>
  ```