Hi @rubysimmons63    Also, Falcon is explained in detail in contrast with Atlas here, do check it out for better understanding :- https://community.cloudera.com/t5/Support-Questions/What-is-the-difference-between-Apache-atlas-and-Apache/m-p/122450   https://www.cloudera.com/products/open-source/apache-hadoop/apache-falcon.html   Regards,   ... View more

Hi @ryu ,   We can trigger manual GC in datanode JVM application AFAIK.  The best way to deal with long GC pauses is to allocate right amount of heap memory.  We recommend the formula of - 1gb heap per 1 million blocks. You can get the number of block count from NameNode Webui -> datanode (through ambari or CM). Increase the heap and that should fix your issue.  Do check for "No GC detected" in Datanode logs, if you see those then it could be hardware problem triggering GC.   Does that answers your questions. Let me know   Regards, Vipin ... View more

Hi @Seeker90 ,   The ERROR message that you see  is because you are running ZK in standalone mode. This is more of a warning than ERROR. Invalid configuration, only one server specified (ignoring) Further i see the ZK started properly, However while reading snapshots it throws Exception.  Probable causes of Canary test failure &  ZooKeeper Quorum:   1. Max Client Connections is set too low -  2. Long fsyncs (disk writes) - 3. Insufficient heap (long GCs) -  Try below :-  1. Increasing ZK heap size (maybe undersized heap or if size of snapshots is huge, increasing heap would be good starting point ) 2. Increase maximum number of connection to 300 3. grep for "fsync" in ZK logs. Check if ZK disk is independent.    Does that answers your questions. Do let us know.   Regards,     ... View more

Hi @rocky_tian    Although it appears to be https://issues.apache.org/jira/browse/KUDU-2412  but since you are on el7. Not sure if this jira is valid for your case.   Ensure all the prerequisites  kudu libraries are installed as mentioned in the doc :-  https://kudu.apache.org/docs/installation.html#_install_on_rhel_or_centos_hosts   Related external link -  https://stackoverflow.com/questions/52526013/how-to-read-from-kudu-to-python    Regards, Vipin ... View more

Hi @JeromeAlbin    Looks like https://issues.apache.org/jira/browse/IMPALA-9486   The Error pop up  because you are connecting to Impala anonymously (no user, no password). You can specify a user (even if it's not declared in Kudu), then it should work Please read the page 12 of the following document: https://docs.cloudera.com/documentation/other/connectors/impala-jdbc/2-6-15/Cloudera-JDBC-Driver-for-Impala-Install-Guide.pdf Using User Name ----------------------- This authentication mechanism requires a user name but does not require a password. The user name labels the session, facilitating database tracking.   Does that answer your question ? if yes, then feel free to mark this post "accept as solution"   Regards, vipin ... View more

Hi @Smashedcat32  To give some background on the ZooKeeper Canary, the ServiceMonitor will regularly check the health of the ZooKeeper Service by   1. connecting to the ZooKeeper quorum and locate the leader 2. create a znode 3. read the znode 4 deleting the znode.   If any of these steps fail the ServiceMonitor will report the ZOOKEEPER_CANARY_HEALTH has become bad.   In the health reported above, the reason was "Canary test failed to establish a connection or a client session to the ZooKeeper service", which means it failed on step 1.   The problem could lie in three locations:   1. The ZooKeeper Quorum - Fsync, low GC , Low max client connections 2. The Service Monitor - false reports 3. Network connectivity between the Service Monitor and the ZooKeepers   Now coming to your query regarding canary test commands, i dont think we have it available in docs. You can use the commands from ZK guide to test Example - To verify if the ZK instance is leader echo stat | nc ZOOKEEPER_IP ZOOKEEPER PORT | grep Mode  http://www.corejavaguru.com/bigdata/zookeeper/cli https://zookeeper.apache.org/doc/r3.3.3/zookeeperStarted.html#sc_ConnectingToZooKeeper   ... View more

The disk space occupied by a deleted row is only reclaimable via compaction and  given you have deleted some data and if the space is not reclaimed then probably you are hitting the bug  https://issues.apache.org/jira/browse/KUDU-1625   The jira stands unresolved. However if the goal is to delete the data and reclaim disk space, then you can drop partition (if range partition) in order to reclaim space.    Tombstone tablets have all their data removed from disk and don't consume significant resources. These tablet are necessary for correct operation of kudu. See - https://docs.cloudera.com/runtime/7.1.0/troubleshooting-kudu/topics/kudu-tombstoned-or-stopped-tablet-replicas.html   ... View more

Ideally if you have dropped the table then the data should get deleted immediately. The metrics in CM may take some time to reflect, we can verify from backend if the table is actually deleted.    Verify if the table still exist in kudu FS. You can verify this by using kudu ksck command with -tables flags :- kudu cluster ksck <master_addresses> -tables=<tables>   Note if the table created through impala use "impala::db.tablename"   If you see the table in ksck then run below command to delete the table from kudu:- kudu table delete <master_addresses> <table_name>    ... View more

HI @vidanimegh    Ensure if you are able to do forward and reverse dns lookup., Iptables are off. Perform CM agent hard restart.  Whats the java version, There's this bug https://bugs.openjdk.java.net/browse/JDK-8215032 wherein Servers with Kerberos enabled stop functioning. That could be a possibility     ... View more