Problem: Phoenix query using PERCENTILE_CONT fails with NullPointerException For example: CREATE TABLE IF NOT EXISTS P_C ( COL1 INTEGER NOT NULL PRIMARY KEY, COL2 INTEGER ); SELECT PERCENTILE_CONT (0.99) WITHIN GROUP (ORDER BY COL2 ASC) FROM P_C; java.lang.NullPointerException at org.apache.phoenix.expression.aggregator.PercentileClientAggregator.evaluate(PercentileClientAggregator.java:82) at org.apache.phoenix.schema.KeyValueSchema.toBytes(KeyValueSchema.java:112) at org.apache.phoenix.schema.KeyValueSchema.toBytes(KeyValueSchema.java:93) at org.apache.phoenix.expression.aggregator.Aggregators.toBytes(Aggregators.java:109) at org.apache.phoenix.iterate.UngroupedAggregatingResultIterator.next(UngroupedAggregatingResultIterator.java:44) at org.apache.phoenix.jdbc.PhoenixResultSet.next(PhoenixResultSet.java:778) at sqlline.BufferedRows.<init>(BufferedRows.java:37) at sqlline.SqlLine.print(SqlLine.java:1650) at sqlline.Commands.execute(Commands.java:833) at sqlline.Commands.sql(Commands.java:732) at sqlline.SqlLine.dispatch(SqlLine.java:808) at sqlline.SqlLine.begin(SqlLine.java:681) at sqlline.SqlLine.start(SqlLine.java:398) at sqlline.SqlLine.main(SqlLine.java:292) Solution: This is BUG-82044. There is no solution as yet. ... View more

Problem: hbase hbck fails with the following messages zookeeper.ClientCnxn: SASL configuration failed: javax.security.auth.login.LoginException: Zookeeper client cannot authenticate using the 'Client' section of the supplied JAAS configuration: '/usr/hdp/current/hbase-client/conf/hbase_regionserver_jaas.conf' because of a RuntimeException: java.lang.SecurityException: java.io.IOException: /usr/hdp/current/hbase-client/conf/hbase_regionserver_jaas.conf (No such file or directory) 017-06-11 10:11:36,293 ERROR [main] master.TableLockManager: Unexpected ZooKeeper error when listing children org.apache.zookeeper.KeeperException$NoAuthException: KeeperErrorCode = NoAuth for /hbase-secure/table-lock at org.apache.zookeeper.KeeperException.create(KeeperException.java:113) at org.apache.zookeeper.KeeperException.create(KeeperException.java:51) Solution: Identify the location of the jaas file and set it in the HBASE_SERVER_JAAS_OPTS parameter, make sure it exists, then set the HBASE_SERVER_JAAS_OPTS parameter. grep -i jaas /etc/hbase/conf/hbase-env.sh export HBASE_MASTER_OPTS="$HBASE_MASTER_OPTS -Xmx512m -Djava.security.auth.login.config=/usr/hdp/current/hbase-client/conf/hbase_master_jaas.conf $JDK_DEPENDED_OPTS" # ls -altr /usr/hdp/current/hbase-client/conf/hbase_master_jaas.conf -rw-r--r-- 1 hbase root 209 May 8 01:53 /usr/hdp/current/hbase-client/conf/hbase_master_jaas.conf export HBASE_SERVER_JAAS_OPTS=-Djava.security.auth.login.config=/usr/hdp/current/hbase-client/conf/hbase_master_jaas.conf Now re-run the hbase hbck. ... View more

Problem: Running a query in Hive View in Ambari, rows 1 to 100 are shown, then the next page starts at 102. For example, first screen: Second screen: Resolution: This is bug AMBARI-19666 which is fixed in Ambari 2.4.3 and later. ... View more

Performing a sqoop import using 'hive-import' into a data type char() or varchar() fails with 17/06/05 14:04:44 INFO mapreduce.Job: Task Id : attempt_1496415095220_0016_m_000002_0, Status : FAILED Error: java.lang.ClassNotFoundException: org.apache.hadoop.hive.serde2.SerDeException at java.net.URLClassLoader.findClass(URLClassLoader.java:381) Working example. Create the Teradata and hive tables as follows: Terdata> create table td_importme_into_hive (col1 int not null primary key, col2 char(30)); Hive> create table td_import (col1 int, col2 char(30)); Execute sqoop import --connection-manager {connection info} \ --table td_importme_into_hive --hive-import --hive-table td_import \ -m 1 --split-by col1 This will fail as char / varchar are not supported Hive datatypes for sqoop import from Teradata. Create the hive table with datatype string instead of char() or varchar(). ... View more

Problem: Certain arithmetic operations return the wrong result in Phoenix. For example: 0: jdbc:phoenix:> select 2/4 ; +----+ | 0 | +----+ | 0 | +----+ 1 row selected (0.014 seconds) Cause: This is because the result is returned as an int rather than a decimal See PHOENIX-3312 Workaround: Provide decimal values within the SQL e.g. 0: jdbc:phoenix:> select 2.0/4.0 ; +------+ | 0.5 | +------+ | 0.5 | +------+ 1 row selected (0.011 seconds) ... View more

Question: Are there any functions which allow date arithmetic with phoenix? Answer: this is done as a fraction of a day. e.g. to add 12 hours to a day: > select now(), now() + (0.5) ; +---------------------------------+---------------------------------+ | DATE '2017-06-04 16:55:07.989' | DATE '2017-06-05 04:55:07.989' | +---------------------------------+---------------------------------+ | 2017-06-04 16:55:07.989 | 2017-06-05 04:55:07.989 | +---------------------------------+---------------------------------+ To add 15 minutes you would use (15/1440). ie. 0: jdbc:phoenix:> select now(), now() + (0.010416666666667) ; +---------------------------------+---------------------------------+ | DATE '2017-06-04 16:56:31.492' | DATE '2017-06-04 17:11:31.492' | +---------------------------------+---------------------------------+ | 2017-06-04 16:56:31.492 | 2017-06-04 17:11:31.492 | +---------------------------------+---------------------------------+ 1 row selected (0.024 seconds) See also: RMP-9148 "Provide Date arithmetic functions for Phoenix" ... View more

Assuming you start with a kerberized HDP cluster with Hbase installed. First check what your hbase service principal is i.e. klist -kt /etc/security/keytabs/hbase.service.keytab Keytab name: FILE:hbase.service.keytab KVNO Timestamp Principal ---- ----------------- -------------------------------------------------------- 2 12/20/16 13:51:21 hbase/hdp253k1.hdp@HDP.COM 2 12/20/16 13:51:21 hbase/hdp253k1.hdp@HDP.COM 2 12/20/16 13:51:21 hbase/hdp253k1.hdp@HDP.COM 2 12/20/16 13:51:21 hbase/hdp253k1.hdp@HDP.COM 2 12/20/16 13:51:21 hbase/hdp253k1.hdp@HDP.COM In Ambari head to Hbase -> Configs -> Advanced -> Custom Hbase-Site.xml and add the following new parameters with the keytab / principal substituted for your environment. If they already exist for your cluster set the values as indicated: hbase.rest.authentication.type=kerberos hbase.master.kerberos.principal=hbase/_HOST@HDP.COM hbase.master.keytab.file=/etc/security/keytabs/hbase.service.keytab hadoop.proxyuser.HTTP.groups=* hadoop.proxyuser.HTTP.hosts=* hbase.security.authorization=true hbase.rest.authentication.kerberos.keytab=/etc/security/keytabs/spnego.service.keytab hbase.rest.authentication.kerberos.principal=HTTP/_HOST@HDP.COM hbase.security.authentication=kerberos hbase.rest.kerberos.principal=hbase/_HOST@HDP.COM hbase.rest.keytab.file=/etc/security/keytabs/hbase.service.keytab In Ambari -> HDFS, confirm that the following are set and if not add them to 'Custom core-site.xml' hadoop.proxyuser.HTTP.groups=* hadoop.proxyuser.HTTP.hosts=* Restart the affected HBase & HDFS services. On the command line on the HBase master, kinit with the service keytab and start the REST server: su - hbase kinit -kt hbase.service.keytab hbase/hdp253k1.hdp@HDP.COM /usr/hdp/current/hbase-master/bin/hbase-daemon.sh start rest -p 17000 --infoport 17050 Test the REST server without / with a ticket as follows: # kdestroy # klist klist: No credentials cache found (ticket cache FILE:/tmp/krb5cc_0) # curl --negotiate -u : 'http://hdp253k1.hdp:17000/status/cluster' <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"/> <title>Error 401 Authentication required</title> # kinit -kt hbase.service.keytab hbase/hdp253k1.hdp@HDP.COM # curl --negotiate -u : 'http://aw253k1:17000/status/cluster' 3 live servers, 0 dead servers, 10.6667 average load 3 live servers     hdp253k1.hdp:16020 1490688381983         requests=0, regions=11         heapSizeMB=120        maxHeapSizeMB=502 ... View more

Depends on whether we are talking about under HDFS or at the OS level, but the answer to both is Yes... For accounts under HDFS, the home directory is determined by the value of dfs.user.home.dir.prefix. see: https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml For OS users you can pre-create your service users before install, then set ignore_groupsusers_create=true in cluster-env.xml, and then launch the installer. The service users and groups are here: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.5.3/bk_command-line-installation/content/create-system-users-and-groups.html ... View more

Q: Is there any way to change the user my hive jobs run as under LLAP? They always seem to run as 'hive' user. A: Hive LLAP does not currently support hive.server2.enable.doAs=true. All sessions will run under the hive account. ... View more

Assuming you start with a kerberized HDP cluster with Hbase installed. First check what your service principal is i.e. klist -kt /etc/security/keytabs/hbase.service.keytab Keytab name: FILE:hbase.service.keytab KVNO Timestamp Principal ---- ----------------- -------------------------------------------------------- 2 12/20/16 13:51:21 hbase/hdp252.hdp@HWX.COM 2 12/20/16 13:51:21 hbase/hdp252.hdp@HWX.COM 2 12/20/16 13:51:21 hbase/hdp252.hdp@HWX.COM 2 12/20/16 13:51:21 hbase/hdp252.hdp@HWX.COM 2 12/20/16 13:51:21 hbase/hdp252.hdp@HWX.COM In Ambari head to Hbase -> Configs -> Advanced -> Custom Hbase-Site.xml and add the following new parameters with the keytab / principal substituted: hbase.thrift.security.qop=auth hbase.thrift.support.proxyuser=true hbase.regionserver.thrift.http=true hbase.thrift.keytab.file=/etc/security/keytabs/hbase.service.keytab hbase.thrift.kerberos.principal=hbase/_HOST@HWX.COM hbase.security.authentication.spnego.kerberos.keytab=/etc/security/keytabs/spnego.service.keytab hbase.security.authentication.spnego.kerberos.principal=HTTP/_HOST@HDP.COM Check that the following are set in HDFS and if not, add them to 'Custom core-site.xml' hadoop.proxyuser.hbase.groups=* hadoop.proxyuser.hbase.hosts=* Restart the affected HBase & HDFS services. On the command line on the HBase master, kinit with the service keytab and start the thrift server: su - hbase kinit -kt hbase.service.keytab hbase/hdp252.hdp@HWX.COM/usr/hdp/current/hbase-master/bin/hbase-daemon.sh start thrift --infoport 8086 The parameter we set earlier 'hbase.regionserver.thrift.http=true' indicates that the thrift server will be started in http mode. To start in binary mode set this to false. Logs are written to /var/log/hbase and you should see a running process To test the thrift server in http mode the syntax is: hbase org.apache.hadoop.hbase.thrift.HttpDoAsClient hdp252 9090 hbase true to test in binary mode the syntax is: hbase org.apache.hadoop.hbase.thrift.DemoClient hdp252 9090 true ... View more

Problem: Following upgrade to 2.5 Oozie Sqoop job which previously worked now fails with oozi-W@sqoop-aa6c] Launcher exception: org/json/JSONObject java.lang.NoClassDefFoundError: org/json/JSONObject at org.apache.sqoop.util.SqoopJsonUtil.getJsonStringforMap(SqoopJsonUtil.java:43) at org.apache.sqoop.SqoopOptions.writeProperties(SqoopOptions.java:759) at org.apache.sqoop.metastore.hsqldb.HsqldbJobStorage.createInternal(HsqldbJobStorage.java:399) at org.apache.sqoop.metastore.hsqldb.HsqldbJobStorage.create(HsqldbJobStorage.java:379) Solution: Ensure that 'java-json.jar' file exists in the following locations: /usr/hdp/current/sqoop-client/lib /usr/hdp/<version>/sqoop/lib Also copy this jar into HDFS and reference it in your oozie workflow: e.g. hdfs dfs -put /usr/hdp/current/sqoop-client/lib/java-json.jar /user/oozie/oozie_scripts/lib/ and change workflow.xml: <archive>/user/oozie/oozie_scripts/lib/java-json.jar#java-json.jar</archive> ... View more

It would sometimes be useful to adjust the log level when executing hbase client commands from command line without having to restart components. This article explains how that can be achieved: You can set DEBUG level for any client hbase command by exporting the following environment variable before it is executed: HBASE_ROOT_LOGGER=hbase.root.logger=DEBUG,console For example: # export HBASE_ROOT_LOGGER=hbase.root.logger=DEBUG,console # hbase hbck 2016-12-24 15:18:03,240 DEBUG [main] util.Shell: setsid exited with exit code 0 2016-12-24 15:18:03,363 DEBUG [main] lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginSuccess with annotation @org.apache.hadoop.metrics2.annotation.Metric(always=false, about=, sampleName=Ops, type=DEFAULT, value=[Rate of successful kerberos logins and latency (milliseconds)], valueName=Time) 2016-12-24 15:18:03,373 DEBUG [main] lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginFailure with annotation @org.apache.hadoop.metrics2.annotation.Metric(always=false, about=, sampleName=Ops, type=DEFAULT, value=[Rate of failed kerberos logins and latency (milliseconds)], valueName=Time) 2016-12-24 15:18:03,373 DEBUG [main] lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.getGroups with annotation @org.apache.hadoop.metrics2.annotation.Metric(always=false, about=, sampleName=Ops, type=DEFAULT, value=[GetGroups], valueName=Time) 2016-12-24 15:18:03,375 DEBUG [main] impl.MetricsSystemImpl: UgiMetrics, User and group related metrics 2016-12-24 15:18:03,407 DEBUG [main] security.SecurityUtil: Setting hadoop.security.token.service.use_ip to true 2016-12-24 15:18:03,443 DEBUG [main] security.Groups: Creating new Groups object 2016-12-24 15:18:03,447 DEBUG [main] util.NativeCodeLoader: Trying to load the custom-built native-hadoop library... 2016-12-24 15:18:03,447 DEBUG [main] util.NativeCodeLoader: Loaded the native-hadoop library 2016-12-24 15:18:03,452 DEBUG [main] security.JniBasedUnixGroupsMapping: Using JniBasedUnixGroupsMapping for Group resolution 2016-12-24 15:18:03,452 DEBUG [main] security.JniBasedUnixGroupsMappingWithFallback: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMapping 2016-12-24 15:18:03,542 DEBUG [main] security.Groups: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMappingWithFallback; cacheTimeout=300000; warningDeltaMs=5000 2016-12-24 15:18:03,644 DEBUG [main] security.UserGroupInformation: hadoop login 2016-12-24 15:18:03,647 DEBUG [main] security.UserGroupInformation: hadoop login commit 2016-12-24 15:18:03,649 DEBUG [main] security.UserGroupInformation: using kerberos user:hbase/dghdp253.openstacklocal@HWX.COM 2016-12-24 15:18:03,649 DEBUG [main] security.UserGroupInformation: Using user: "hbase/dghdp253.openstacklocal@HWX.COM" with name hbase/dghdp253.openstacklocal@HWX.COM 2016-12-24 15:18:03,650 DEBUG [main] security.UserGroupInformation: User entry: "hbase/dghdp253.openstacklocal@HWX.COM" 2016-12-24 15:18:03,653 DEBUG [main] security.UserGroupInformation: UGI loginUser:hbase/dghdp253.openstacklocal@HWX.COM (auth:KERBEROS) <snip> Note, the following log levels are supported: ALL DEBUG ERROR FATAL INFO OFF TRACE TRACE_INT WARN ... View more

It would sometimes be useful to adjust the log level when executing hive commands from command line without having to restart components. This article explains how that can be achieved: You can provide the log level on the command line to hive as follows hive -hiveconf hive.root.logger=DEBUG,console -e "show tables ;" For example: # hive -hiveconf hive.root.logger=DEBUG,console -e "show tables ;" |more 16/12/24 15:10:23 DEBUG util.VersionInfo: version: 2.7.3.2.5.3.0-37 16/12/24 15:10:27 [main]: DEBUG common.LogUtils: Using hive-site.xml found on CLASSPATH at /etc/hive/2.5.3.0-37/0/hive-site.xml 16/12/24 15:10:27 [main]: DEBUG session.SessionState: SessionState user: null Logging initialized using configuration in file:/etc/hive/2.5.3.0-37/0/hive-log4j.properties 16/12/24 15:10:27 [main]: INFO SessionState: Logging initialized using configuration in file:/etc/hive/2.5.3.0-37/0/hive-log4j.properties 16/12/24 15:10:27 [main]: DEBUG parse.VariableSubstitution: Substitution is on: hive 16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginSuccess with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[Rate of successful kerberos logins and latency (milliseconds)]) 16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginFailure with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[Rate of failed kerberos logins and latency (milliseconds)]) 16/12/24 15:10:27 [main]: DEBUG lib.MutableMetricsFactory: field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.getGroups with annotation @org.apache.hadoop.metrics2.annotation.Metric(about=, sampleName=Ops, always=false, type=DEFAULT, valueName=Time, value=[GetGroups]) This can be especially useful if your hive cli is hanging or slow connecting. Note, the following log levels are supported: ALL DEBUG ERROR FATAL INFO OFF TRACE TRACE_INT WARN ... View more

It's sometimes useful to adjust the log level when executing commands from the client to get more info about what is happening. This article explains how that can be achieved: You can set DEBUG level for any client command by exporting the following environment variable before it is executed: HADOOP_ROOT_LOGGER=hadoop.root.logger=DEBUG,console Now try executing a client command and watch the stream of DEBUG info come to your terminal. For example: # hdfs dfs -ls 16/12/24 15:01:34 DEBUG util.Shell: setsid exited with exit code 0 16/12/24 15:01:34 DEBUG conf.Configuration: parsing URL jar:file:/usr/hdp/2.5.3.0-37/hadoop/hadoop-common-2.7.3.2.5.3.0-37.jar!/core-default.xml 16/12/24 15:01:34 DEBUG conf.Configuration: parsing input stream sun.net.www.protocol.jar.JarURLConnection$JarURLInputStream@149494d8 16/12/24 15:01:34 DEBUG conf.Configuration: parsing URL file:/etc/hadoop/2.5.3.0-37/0/core-site.xml 16/12/24 15:01:34 DEBUG conf.Configuration: parsing input stream java.io.BufferedInputStream@28c4711c 16/12/24 15:01:35 DEBUG security.SecurityUtil: Setting hadoop.security.token.service.use_ip to true 16/12/24 15:01:35 DEBUG security.Groups: Creating new Groups object 16/12/24 15:01:35 DEBUG util.NativeCodeLoader: Trying to load the custom-built native-hadoop library... 16/12/24 15:01:35 DEBUG util.NativeCodeLoader: Loaded the native-hadoop library 16/12/24 15:01:35 DEBUG security.JniBasedUnixGroupsMapping: Using JniBasedUnixGroupsMapping for Group resolution 16/12/24 15:01:35 DEBUG security.JniBasedUnixGroupsMappingWithFallback: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMapping 16/12/24 15:01:35 DEBUG security.Groups: Group mapping impl=org.apache.hadoop.security.JniBasedUnixGroupsMappingWithFallback; cacheTimeout=300000; warningDeltaMs=5000 16/12/24 15:01:35 DEBUG security.UserGroupInformation: hadoop login 16/12/24 15:01:35 DEBUG security.UserGroupInformation: hadoop login commit 16/12/24 15:01:35 DEBUG security.UserGroupInformation: using kerberos user:hdfs-emeasupport@HWX.COM 16/12/24 15:01:35 DEBUG security.UserGroupInformation: Using user: "hdfs-emeasupport@HWX.COM" with name hdfs-emeasupport@HWX.COM 16/12/24 15:01:35 DEBUG security.UserGroupInformation: User entry: "hdfs-emeasupport@HWX.COM" 16/12/24 15:01:35 DEBUG security.UserGroupInformation: UGI loginUser:hdfs-emeasupport@HWX.COM (auth:KERBEROS) <snip> Note, the following log levels are supported: ALL DEBUG ERROR FATAL INFO OFF TRACE TRACE_INT WARN ... View more

What is the recommendation for disk configuration for the file channel with flume? I read that even if just one of disks involved in a disk channel which flume is writing to fails the channel may not be able to recover any of the data—even events that are on disks that have not failed. So for this reason, perhaps RAID-ed disks may be preferred? ... View more