Tutorial of Nereids minidump

Minidump is a basic dump file for Nereids optimizer which arms
to replay problems and used as unit test tool for developers.
It include minimal necessary informations for Nereids optimizer
to replay a scenario in Optimizer.

Save minidump file

In two cases fe would save minidump file

• when query throw an exception
• when use ‘set enable_minidump=true;’ switch by User

File structure of minidump file

Minidump files would save in $DORIS_HOME/log/minidump path
and named by queryId like: c9bf82b70ce34c28-8d281e31412f3ee6.json
File structure of minidump file includes:
| key | Value |
|:----|:----|
|Sql | original sql string |
|SessionVariables | sessionVariables different than default |
|DatabaseName | database name|
|Tables | schemas in table, partition info and some table properties | |ColocateTableIndex | table distribute informations |
|ColumnStatistics | all ColumnStatistics in table |
|Histogram | all histogram information in table|
|ParsedPlan | plan after parsed in json format|
|ResultPlan | plan after all optimized in json format|

Use of nereids_ut.sh

When we want to use this shell, we need to go to output/fe/minidump path
Now only one parameter is allowed for this shell which is directory
of minidump files like $DORIS_HOME/log/minidump

cd output/fe/minidump
./nereids_ut.sh --d $minidump_files_path

The running reports can be found in output/fe/minidump/log
which is minidump.out