e22a9ecc3b
* [enhancement](execute model) using thread pool to execute report or join task instead of staring too many thread Doris will start report thread and join thread during fragment execution. There are many problems if create and destroy thread very frequently. Jemalloc may not behave very well, it may crashed. jemalloc/jemalloc#1405 It is better to using thread pool to do these tasks. --------- Co-authored-by: yiguolei <yiguolei@gmail.com>