This PR proposes mapping external catalog JSON types to String instead of JsonB in Apache Doris. This change is motivated by the realization that JDBC retrieves JSON data as a String JSON string, regardless of its storage format (Json(String) or Json(Binary)). Mapping to String streamlines data retrieval, simplifies write-backs, and ensures compatibility with all JSON(String) and JSON(Binary) functions, despite potentially misleading displays of JSON data as Strings in Doris. This approach avoids the performance overhead and complexity of converting each row of data from JsonB to String, making the process more efficient and elegant.
About Upgrade
To ensure query compatibility with existing Catalogs in the upgraded version,we currently still retain the capability to query external JSON types as JSONB. However, once you upgrade to the new version and either refresh the Catalog or create a new one, all external JSON types will be treated as Strings. To ensure consistent behavior,and possible future removal of support for JSON as JSONB query code, it is highly recommended that you manually refresh your Catalog as soon as possible after upgrading to the new version.
1. we need remove BE kinit, and use jni login with keytab, because kinit cannot renew TGT for doris in many complex cases.
> This pull requet will support new instance from keytab: https://github.com/apache/doris-thirdparty/pull/173, so now we won't need kinit cmd, just login with keytab and principal
2. add `kerberos_ccache_path` to set kerberos credentials cache path manually.
3. add `max_hdfs_file_handle_cache_time_ms` to set hdfs fs handle cache time.
Although serving_blocks_num is an atomic variable. It's ++ and -- are not protected by transfer lock.
I am not sure the memory order of ++ and --.
I think it maybe the root cause of query timeout. So that I remove the check and test it in github pipeline.
The following cases are unstable.
1. LoadStreamMgrTest
2. TaskWorkerPoolTest.PriorTaskWorkerPool
Rationales
1. LoadStreamMgrTest
It is related to timeout. If we investigate the examples in BRPC, we will find the timeout is usually set to 0 rather than a specific number.
2. TaskWorkerPoolTest.PriorTaskWorkerPool
The order of the threads for the lock contentions is undetermined.
