I have propose a lookup ,but i found i could not use it.
i would met the exception.
Unknown exception / Lookup [id_to_join_time] not found / java.lang.NullPointerException / on host slave4:80
Then i open the broker log ,and to find some solutions.
here is some log as follows.
2019-09-04T06:00:31,080 ERROR [LookupExtractorFactoryContainerProvider-MainThread] org.apache.druid.query.lookup.LookupReferencesManager - Exception occured while handling lookup notice, with message [start method returned false for lookup [id_to_join_time]:[LookupExtractorFactoryContainer{version=‘v2’, lookupExtractorFactory=NamespaceLookupExtractorFactory{extractionNamespace=JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}, firstCacheTimeout=120000, injective=false, extractorID=‘namespace-factory-JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}-336ca175-cc8c-45cf-9ed1-9042b6881791’}}]].: {class=org.apache.druid.query.lookup.LookupReferencesManager}
2019-09-04T06:08:31,358 ERROR [LookupExtractorFactoryContainerProvider-MainThread] org.apache.druid.query.lookup.LookupReferencesManager - Exception occured while handling lookup notice [LoadNotice{lookupName=‘id_to_join_time’, lookupExtractorFactoryContainer=LookupExtractorFactoryContainer{version=‘v2’, lookupExtractorFactory=NamespaceLookupExtractorFactory{extractionNamespace=JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}, firstCacheTimeout=120000, injective=false, extractorID=‘namespace-factory-JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}-e34dc9aa-5076-4c40-9bb4-d46af5d20809’}}}].
org.apache.druid.java.util.common.ISE: start method returned false for lookup [id_to_join_time]:[LookupExtractorFactoryContainer{version=‘v2’, lookupExtractorFactory=NamespaceLookupExtractorFactory{extractionNamespace=JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}, firstCacheTimeout=120000, injective=false, extractorID=‘namespace-factory-JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}-e34dc9aa-5076-4c40-9bb4-d46af5d20809’}}]
2019-09-04T06:08:31,359 ERROR [LookupExtractorFactoryContainerProvider-MainThread] org.apache.druid.query.lookup.LookupReferencesManager - Exception occured while handling lookup notice, with message [start method returned false for lookup [id_to_join_time]:[LookupExtractorFactoryContainer{version=‘v2’, lookupExtractorFactory=NamespaceLookupExtractorFactory{extractionNamespace=JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}, firstCacheTimeout=120000, injective=false, extractorID=‘namespace-factory-JdbcExtractionNamespace{connectorConfig=DbConnectorConfig{createTables=true, connectURI=‘jdbc:mysql://117.139.13.64:3306/dev’, user=‘bigdata_ro’, passwordProvider=org.apache.druid.metadata.DefaultPasswordProvider, dbcpProperties=null}, table=‘ods_klicen_app_dev_base_users’, keyColumn=‘id’, valueColumn=‘join_time’, tsColumn=‘null’, filter=‘null’, pollPeriod=PT0S}-e34dc9aa-5076-4c40-9bb4-d46af5d20809’}}]].: {class=org.apache.druid.query.lookup.LookupReferencesManager}
join_time FROM ods_klicen_app_dev_base_users WHERE join_time IS NOT NULL", arguments:{ positional:{}, named:{}, finder:}]
Caused by: org.skife.jdbi.v2.exceptions.ResultSetException: Exception thrown while attempting to traverse the result set [statement:“SELECT id, join_time FROM ods_klicen_app_dev_base_usersWHERE join_time IS NOT NULL”, located:“SELECT id, join_time FROM ods_klicen_app_dev_base_users WHERE join_time IS NOT NULL”, rewritten:“SELECT id, join_time FROM ods_klicen_app_dev_base_users WHERE join_time IS NOT NULL”, arguments:{ positional:{}, named:{}, finder:}]