* SQL: Ditch CalciteConnection layer and add DruidMeta, extension aggregators.
Switched from CalciteConnection to Planner, bringing benefits:
- CalciteConnection's JDBC interface no longer sits between the SQL server
(HTTP/Avatica) and Druid's query layer. Instead, the SQL servers can use
Druid Sequence objects directly, reducing overhead in the query return path.
- Implemented our own Planner-based Avatica Meta, letting us control
connection timeouts and connection / statement limits. The previous
CalciteConnection-based implementation didn't have any limits or timeouts.
- The Planner interface lets us override the operator table, opening up
SQL language extensions. This patch includes two: APPROX_COUNT_DISTINCT
in core, and a QUANTILE aggregator in the druid-histogram extension.
Also:
- Added INFORMATION_SCHEMA metadata schema.
- Added tests for Unicode literals and escapes.
* Verify statement is actually open before closing it.
* More detailed INFORMATION_SCHEMA docs.
* SQL support for nested groupBys.
Allows, for example, doing exact count distinct by writing:
SELECT COUNT(*) FROM (SELECT DISTINCT col FROM druid.foo)
Contrast with approximate count distinct, which is:
SELECT COUNT(DISTINCT col) FROM druid.foo
* Add deeply-nested groupBy docs, tests, and maxQueryCount config.
* Extract magic constants into statics.
* Rework rules to put preconditions in the "matches" method.
* allow JsonConfigTesterBase to treat the fields of collections
* [Feature] Exhibitor Support (#3664)
This patch provides the integration of Druid & Netflix Exhibitor. Druid
currently use Apache Curator as ZooKeeper client. Curator can be
integrated with Exhibitor to achieve a live/updating list of the
ZooKeeper ensemble. This patch enables Druid to use this features.
* Add metrics for Query Count statistics
This PR adds a new metrics monitor “QueryCountStatsMonitor” which emits
three new metrics -
1) query/success/count - number of successful queries
2) query/failed/count - number of failed queries
3) query/interrupted/count - number of interrupted/timedout queries
fix bindings
* make fields final
* fix imports
* AsyncQueryForwardingServlet implement QueryStatsProvider
* remove unused import
* Normalized Cost Balancer
* Adding documentation and renaming to use diskNormalizedCostBalancer
* Remove balancer from the strings
* Update docs and include random cost balancer
* Fix checkstyle issues
* Blacklist workers if they fail for too many times
* Adding documentation
* Changing to timeout to period and updating docs
* 1. Add configurable maxPercentageBlacklistWorkers
2. Rename variable
* Change maxPercentageBlacklistWorkers to double
* Remove thread.sleep
This patch introduces a GroupByStrategy concept and two strategies: "v1"
is the current groupBy strategy and "v2" is a new one. It also introduces
a merge buffers concept in DruidProcessingModule, to try to better
manage memory used for merging.
Both of these are described in more detail in #2987.
There are two goals of this patch:
1. Make it possible for historical/realtime nodes to return larger groupBy
result sets, faster, with better memory management.
2. Make it possible for brokers to merge streams when there are no order-by
columns, avoiding materialization.
This patch does not do anything to help with memory management on the broker
when there are order-by columns or when there are nested queries. That could
potentially be done in a future patch.
* make isSingleThreaded groupBy query processing overridable at query time
* refactor code in GroupByMergedQueryRunner to make processing of single threaded and parallel merging of runners consistent
* Add back FilteredServerView removed in a32906c7fd to reduce memory usage using watched tiers.
* Add functionality to specify "druid.broker.segment.watchedDataSources"
This PR changes the retry of task actions to be a bit more aggressive
by reducing the maxWait. Current defaults were 1 min to 10 mins, which
lead to a very delayed recovery in case there are any transient network
issues between the overlord and the peons.
doc changes.
Niketh Sabbineni
Gian Merlino
Vinh Tran
Yuusaku Taniguchi
Himanshu
Nishant
Erik Dubbelboer
Navis Ryu
Charles Allen
David Lim
Fangjin Yang
Parag Jain
binlijin
Bingkun Guo
Robin
Parag Jain
Jonathan Wei