Why is this needed? DBA's need to be able to:
- Identify commonly used queries
- Identify opportunities for SQL tuning
- Identify resource utilization issues
- Identify table/projection usage
- Track table/projection disk space usage growth over time.
Also, Developers and Data Architects may not have pseudosuperuser rights on the production database, but will want to know how their applications perform in production so that they can tune them.
There are several monitoring tools that work with Linux/Vertica such as:
- Management Console
- Ganglia
- Cacti
This tool is designed to complement these monitoring tools. It creates a set of SQL tables to capture historical data from the v_monitor and data collector tables. These tables are updated by SQL scripts, and a collection of diagnostic views sit on top of these tables to provide the DBA with insights into the Vertica database.
###Current - Not sourced from history tables
- vProjectionUsage
- vProjectionColumnSize
- vRunningQueries
- vLongRunningQueries
- vQueryPlanProfiles
- vMostCommonQueries
###Historical - Combine current data with historical
- vProjectionSizeHistory
- vProjectionUsageHistory
- vLongRunningQueriesHistory
- vProjectionGrowthOverTimeWeekly
###Tables sourced from v_monitor schema
- execution_engine_profiles
- query_profiles
- query_plan_profiles
- query_requests
- query_events
- resource_rejection_details
- user_sessions
- transactions
- load_streams
- projection_storage
- projection_usage
- system_resource_usage
- resource_acquisitions
###Tables sourced from Data Collector
- dc_execution_engine_events
- /bin - bash shell scripts, typically called through cron jobs
- /bin/ahm_lag_alert.sh - raises an alert when ahm is 4 hours behind
- /bin/vmart_vertica2vertica_parallel_load.sh - parallel loader for copying tables to Vertica from Vertica
- /sql - sql scripts
- /sql/ddl - one time setup (DDL)
- /sql/merge - SQL scripts
- /sql/merge/load_vstb_tables.sql - Loads historical tables in vstb schema
- /sql/merge/update_statistics.sql - Updates stats on tables missing stats
- /sql/merge/purge_deleted_records.sql - Purges deleted records from tables
- /log - log files are stored here. You will need to create this.
###Why not modify the history retention parameter in the data collector tables? An alternative to creating custom history tables is to find the data collection table that make up the v_monitor objects and extend the history retention period for those tables.
You can see how much history is retained in each data collector table by either querying the time field in each dc table or looking at this view:
SELECT * FROM v_monitor.data_collector ORDER BY 3,1;
You can use EXPLAIN to find the data collector tables used by each v_monitor table
EXPLAIN SELECT * FROM v_monitor.query_plan_profiles;
This package gives us the capability to save disk space by only capturing history for specific events.
###Why do you strip out carriage returns, line feeds and tabs from the query string? Stripping out these characters makes it possible to copy and paste the results into Excel using Excel's default parsing options. If we left those characters in then columns would be misaligned. You can reformat the SQL using an automated formatting tool such as the Poor Man's T-SQL Formatter plugin for notepad++.