question Re: How to troubleshoot slow NameNode start up? in Support Questions

question Re: How to troubleshoot slow NameNode start up? in Support Questions https://community.cloudera.com/t5/Support-Questions/How-to-troubleshoot-slow-NameNode-start-up/m-p/281531#M209427 <a href="https://community.cloudera.com/t5/user/viewprofilepage/user-id/52124">@Elephanta</a> The name node start is usually faster than what you are experiencing frm the logs I am seeing maybe the root cause. During startup the namenode read the fsimage which is the last best cluster images usually a combination of fsimage and the last edits log.  You will need to combine the current fsimage and the edits log in the below steps.   <LI-CODE lang="java">Name node is in safe mode.</LI-CODE>  When the name node is in this state it's a security future that disables any change that the namenode metadata that it can't register,/record to note all the cluster wise location, state, permissions,ownership etc are stored in the metadata which is stored in the name node. You will need to do the following steps as root user while the cluster is freezing during startup.# su - hdfsGet the current state$ hdfs hdfsadmin -safemode get That will confirm that the namenode is in safe mode, you will need to force the creation of a hdfs image point in time by saving the namespace to create a new fsimage $ hdfs dfsadmin -saveNamespaceconfirm safemode is off$ hdfs hdfsadmin -safemode get This time the output should be Off  leave safe mode and next time the startup should be much faster $ hdfs hdfsadmin -safemode get You might need to tune the memory allocated to the name node it seems the numebr of files to manage has increased hence the need to reconfigure the memory  have a look at the below link for guidance.. <A href="https://www.ibm.com/support/pages/configuring-namenode-heap-size" target="_blank" rel="noopener">Configuring NameNode Heap Size</A> to estimate the memory required for the namenode  Tue, 29 Oct 2019 06:24:42 GMT Shelton 2019-10-29T06:24:42Z