drill

50efb806 - DRILL-5741: Automatically manage memory allocations during startup

DRILL-5741: Automatically manage memory allocations during startup **Note:** This commit is rebased on (hence, requires) DRILL-6068 commit This commit provides a way for distributions and users to automatically define the Drillbit JVM's Heap, Direct and CodeCache allocations. To do this, it leverages the DRILL-6068 commit, which provides for configuration setup. The only new variable introduced is an environment variable - `DRILLBIT_MAX_PROC_MEM` that defines a Drillbit's max memory parameters. The logic defined by `auto-setup.sh` will check that if any (or all) of the JVM memory parameters have been declared; they, cumulatively, don't exceed the value specified by `DRILLBIT_MAX_PROC_MEM`. ``` NOTE: To disable this, simply unset (or don't define) the environment variable DRILLBIT_MAX_PROC_MEM ``` The variable can be defined in KB, MB, or GB; similar in syntax to how the JVM MaxHeap is specified. For e.g. ``` DRILLBIT_MAX_PROC_MEM=13G DRILLBIT_MAX_PROC_MEM=8192m DRILLBIT_MAX_PROC_MEM=4194304K ``` In addition, you can specify it as a percent of the total system memory prior to the Drillbit starting up: `DRILLBIT_MAX_PROC_MEM=40%` For a system with with 48GB free memory, when set to (say) 25% (with settings defined in drill-env.sh), and heap (8GB) and direct (10GB) are defined; the Drillbit fails startup with the following message: ``` 2018-01-03 14:27:57 [WARN] 25% of System Memory (47 GB) translates to 12 GB 2018-01-03 14:27:57 [ERROR] Unable to start Drillbit due to memory constraint violations Total Memory Requested : 19 GB Check the following settings to possibly modify (or increase the Max Memory Permitted): DRILLBIT_MAX_PROC_MEM=25% DRILL_HEAP=8G DRILL_MAX_DIRECT_MEMORY=10G DRILLBIT_CODE_CACHE_SIZE=1024m *NOTE: It is recommended not to specify DRILLBIT_CODE_CACHE_SIZE as this will be auto-computed based on the HeapSize and would not exceed 1GB ``` For all other combinations, the undefined parameters are adjusted to ensure that the total memory allocated is within the value specified by `DRILLBIT_MAX_PROC_MEM`, For a system with with 48GB free memory, when set to (say) 50% (with settings defined in drill-env.sh), and heap (8GB) and direct (10GB) are defined; the Drillbit startup with the following warning: ``` 2018-01-03 14:31:06 [WARN] 50% of System Memory (47 GB) translates to 24 GB 2018-01-03 14:31:06 [WARN] You have an allocation of 4 GB that is currently unused from a total of 24 GB. You can increase your existing memory configuration to use this extra memory DRILLBIT_MAX_PROC_MEM=50% DRILL_HEAP=8G DRILL_MAX_DIRECT_MEMORY=10G DRILLBIT_CODE_CACHE_SIZE=1024m *NOTE: It is recommended not to specify DRILLBIT_CODE_CACHE_SIZE as this will be auto-computed based on the HeapSize and would not exceed 1GB ``` In addition, if the available free memory is less than the allocation, an additional warning is provided under the assumption that the OS will reclaim more free memory when required: ``` 2018-01-03 14:31:06 [WARN] Total Memory Allocation for Drillbit (19GB) exceeds available free memory (11GB) 2018-01-03 14:31:06 [WARN] Drillbit will start up, but can potentially crash due to oversubscribing of system memory. ``` For more details, refer the attachments in https://issues.apache.org/jira/browse/DRILL-5741 Changes to auto configure messaging Publishing final values prior to startup Minor update for printing to console's err stream close apache/drill#1082