 [](https://github.com/yaooqinn/kyuubi/pull/367)      [❨?❩](https://pullrequestbadge.com/?utm_medium=github&utm_source=yaooqinn&utm_campaign=badge_info)<!-- PR-BADGE: PLEASE DO NOT REMOVE THIS COMMENT -->
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### _Why are the changes needed?_
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Currently, the engine starts to check its lifecycle during the session manager's startup without any initial delay. Before the engine gets ready finally, it might trigger self-terminating.
In this PR, we move the checker to the end where the engine is exposed to the servers.
Avoiding errors like:
```
org.apache.hive.service.cli.HiveSQLException: Error operating GET_CATALOGS: java.net.SocketException: Connection reset
at org.apache.hive.jdbc.Utils.verifySuccess(Utils.java:267)
at org.apache.hive.jdbc.Utils.verifySuccess(Utils.java:258)
at org.apache.hive.jdbc.HiveDatabaseMetaData.getCatalogs(HiveDatabaseMetaData.java:142)
at org.apache.kyuubi.operation.BasicIcebergJDBCTests.$anonfun$$init$$2(BasicIcebergJDBCTests.scala:50)
at org.apache.kyuubi.operation.BasicIcebergJDBCTests.$anonfun$$init$$2$adapted(BasicIcebergJDBCTests.scala:48)
at org.apache.kyuubi.operation.JDBCTestUtils.$anonfun$withMultipleConnectionJdbcStatement$3(JDBCTestUtils.scala:43)
at org.apache.kyuubi.operation.JDBCTestUtils.$anonfun$withMultipleConnectionJdbcStatement$3$adapted(JDBCTestUtils.scala:43)
at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:62)
at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:55)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:49)
```
### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible
- [ ] Add screenshots for manual tests if appropriate
- [x] [Run test](https://kyuubi.readthedocs.io/en/latest/tools/testing.html#running-tests) locally before make a pull request
Closes#367 from yaooqinn/engine.
f6a979e [Kent Yao] fix test
9cc561c [Kent Yao] address comment
3d15ab2 [Kent Yao] nit
a85d2e0 [Kent Yao] Engine terminating checker should start after exposed
Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: Kent Yao <yao@apache.org>
4b13f1c551