1. Fix bug that failed to query restored table after schema change.
2. Fix bug that failed to add rollup to restored table.
3. Optimize the info of SHOW ALTER TABLE stmt.
4. Optimize the info of some PROCs.
5. Optimize the tablet checker to avoid adding too much task to scheduler.
1. Add broker load error hub
A broker load error hub will collect error messages in load process and saves them as a file to the specified remote storage via broker. In case that in broker/min/streaming load process, user may not be able to access the error log file in Backend directly.
We also add a new header option: 'enable_hub' in streaming load request, and default is false. Because if we enable the broker load error hub, it will significantly slow down the processing speed of streaming load, due to the visit of remote storage via broker. So use can disable the error load hub using this header option, to avoid slowing down the load speed.
2. Show load error logs by using SHOW LOAD WARNINGS stmt
We also provide a more easy way to get load error logs. We implement 'SHOW LOAD WARNINGS ON 'url'' stmt to show load error logs directly. The 'url' in stmt is provided in 'SHOW LOAD' stmt.
eg:
show load warnings on "http://192.168.1.1:8040/api/_load_error_log?file=__shard_2/error_log_xxx";
3. Support now() function in broker load
User can mapping a column to now() in broker load stmt, which means this column will be filled with time when the ETL started.
4. Support more types of wildcard in broker load
Currently, we only support wildcard '*' to match the file names. wildcard like '/path/to/20190[1-4]*' is not support.
1. Remove all design docs. They will be pushed again after modification.
2. Add streaming load and privilege help docs.
3. Rename palo*.py to doris*.py in gensrc/script/.
2. add 2 new proc '/current_queries' and '/current_backend_instances' to monitor the current running queries.
3. add a manual compaction api on Backend to trigger cumulative or base compaction manually.
4. add Frontend config 'max_bytes_per_broker_scanner' to limit to bytes per one broker scanner. This is to limit the memory cost of a single broker load job
5. add Frontend config 'max_unfinished_load_job' to limit load job number: if number of running load jobs exceed the limit, no more load job is allowed to be submmitted.
6. a log of bug fixed
