Regular Expression URLs useful during NiFi development

https://www.debuggex.com/ 

https://regexr.com/ 

https://regex101.com/ 

http://qfsm.sourceforge.net/download.html 

NiFi using Java Regular Expression Syntax
https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html

Clean up hanging/stuck ambari background operations manually

login ambari database and find out tasking ID required to clean up:

select task_id,role,role_command from host_role_command where status='IN_PROGRESS';
select task_id,role,role_command from host_role_command where status='QUEUED';
select task_id,role,role_command from host_role_command where status='PENDING';

update identified task_id to aborted status:

update host_role_command set status='ABORTED' where task_id in (264,266);

How to enable support for TLS 1.2 in Windows 7 and Windows 8.1

Starting July 1, 2018, support is being removed for TLS 1.0 and 1.1 from Azure VPN Gateway. VPN Gateway will support only TLS 1.2. To maintain support, see the updates to enable support for TLS1.2.

How to enable support for TLS 1.2 in Windows 7 and Windows 8.1:

Open a command prompt with elevated priveleges by right-clicking on Command Prompt and selecting Run as administrator.

Run the following commands in the command prompt:

reg add HKLM\SYSTEM\CurrentControlSet\Services\RasMan\PPP\EAP\13 /v TlsVersion /t REG_DWORD /d 0xfc0
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp" /v DefaultSecureProtocols /t REG_DWORD /d 0xaa0
if %PROCESSOR_ARCHITECTURE% EQU AMD64 reg add "HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp" /v DefaultSecureProtocols /t REG_DWORD /d 0xaa0

Install the following updates:

KB3140245
KB2977292
Reboot the computer.

Reference: https://docs.microsoft.com/en-us/azure/vpn-gateway/point-to-site-about

Install banana dashboard in Cloudera (using CDH6 beta as example)

Step 1: download banana from github
[root@cdh60b ~]# wget https://github.com/lucidworks/banana/archive/release.zip

Step 2: unzip the release file into "/opt/cloudera/parcels/CDH/lib/solr/server/solr-webapp/webapp/"
[root@cdh60b ~]# unzip release.zip 

[root@cdh60b ~]# mv banana-release /opt/cloudera/parcels/CDH/lib/solr/server/solr-webapp/webapp/banana

[root@cdh60b webapp]# ls -l /opt/cloudera/parcels/CDH/lib/solr/server/solr-webapp/webapp/banana/
total 72
-rw-r--r-- 1 root root  665 Jun  4  2017 bower.json
-rw-r--r-- 1 root root 2669 Jun  4  2017 build.xml
-rw-r--r-- 1 root root 2464 Jun  4  2017 CONTRIBUTING.md
-rw-r--r-- 1 root root  262 Jun  4  2017 default.properties
-rw-r--r-- 1 root root 8478 Jun  4  2017 Gruntfile.js
-rw-r--r-- 1 root root 1531 Jun  4  2017 index.html
drwxr-xr-x 2 root root   31 Jun  4  2017 jetty-contexts
-rw-r--r-- 1 root root  610 Jun  4  2017 LICENSE.md
-rw-r--r-- 1 root root 2169 Jun  4  2017 mvn.template
-rw-r--r-- 1 root root 6990 Jun  4  2017 NOTICE.txt
-rw-r--r-- 1 root root 2176 Jun  4  2017 package.json
-rw-r--r-- 1 root root 3369 Jun  4  2017 pom.xml
-rw-r--r-- 1 root root  131 Jun  4  2017 QUICKSTART
-rw-r--r-- 1 root root 9969 Jun  4  2017 README.md
drwxr-xr-x 7 root root  134 Jun  4  2017 resources
drwxr-xr-x 8 root root  107 Jun  4  2017 src
drwxr-xr-x 4 root root  116 Jun  4  2017 test

Step 3, restart SOLR service using Cloudera manager.

http://cdh60b.dbaglobe.com:8983/solr/banana/src/index.html#/dashboard

If you want to save and load dashboards from Solr, then you need to create a collection called banana-int first. For Solr 6, here are the steps:

[donghua@cdh60b ~]$ cd /opt/cloudera/parcels/CDH/lib/solr/bin
[donghua@cdh60b bin]$ ls
init.d                   oom_solr.sh   sentryMigrationTool  solr.cmd    solr.in.cmd  zksynctool.sh
install_solr_service.sh  post          snapshotscli.sh      solrctl.sh  solr.in.sh
log4j.properties         sentrycli.sh  solr                 solrd       zkcli.sh
[donghua@cdh60b bin]$ ./solr create -c banana-int
WARNING: Using _default configset. Data driven schema functionality is enabled by default, which is
         NOT RECOMMENDED for production use.

         To turn it off:
            curl http://localhost:8983/solr/banana-int/config -d '{"set-user-property": {"update.autoCreateFields":"false"}}'

Connecting to ZooKeeper at cdh60b.dbaglobe.com:2181/solr ...
INFO  - 2018-08-21 09:48:58.220; org.apache.solr.client.solrj.impl.ZkClientClusterStateProvider; Cluster at cdh60b.dbaglobe.com:2181/solr ready
Uploading /opt/cloudera/parcels/CDH/lib/solr/server/solr/configsets/_default/conf for config banana-int to ZooKeeper at cdh60b.dbaglobe.com:2181/solr

Creating new collection 'banana-int' using command:
http://localhost:8983/solr/admin/collections?action=CREATE&name=banana-int&numShards=1&replicationFactor=1&maxShardsPerNode=-1&collection.configName=banana-int

{
  "responseHeader":{
    "status":0,
    "QTime":3084},
  "success":{"cdh60b:8983_solr":{
      "responseHeader":{
        "status":0,
        "QTime":1651},
      "core":"banana-int_shard1_replica_n1"}}}

Two methods to create keytab for secure cluster

Method 1: (alternative use kadmin, but not possible with -norandkey option)

[root@cdh60 flume-ng]# kadmin.local 
Authenticating as principal root/admin@DBAGLOBE.COM with password.
kadmin.local:  ktadd -k dsuser.keytab -norandkey dsuser@DBAGLOBE.COM
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type aes256-cts-hmac-sha1-96 added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type aes128-cts-hmac-sha1-96 added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type des3-cbc-sha1 added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type arcfour-hmac added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type camellia256-cts-cmac added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type camellia128-cts-cmac added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type des-hmac-sha1 added to keytab WRFILE:dsuser.keytab.
Entry for principal dsuser@DBAGLOBE.COM with kvno 3, encryption type des-cbc-md5 added to keytab WRFILE:dsuser.keytab.
kadmin.local:  quit

Method 2: works for both MITKDC and AD

[dsuser@cdh60 ~]$ ktutil 
ktutil:  addent -password -p dsuser@DBAGLOBE.COM -k 3 -e aes256-cts-hmac-sha1-96
Password for dsuser@DBAGLOBE.COM: 
ktutil:  wkt /home/dsuser/dsuser.keytab
ktutil:  q

Configure HDFS NFS Gateway

Configure HDFS NFS Gateway

[root@cdh60 ~]# showmount -e cdh60
Export list for cdh60:
/ *

[root@cdh60 ~]# rpcinfo cdh60
   program version netid     address                service    owner
    100000    4    tcp6      ::.0.111               portmapper superuser
    100000    3    tcp6      ::.0.111               portmapper superuser
    100000    4    udp6      ::.0.111               portmapper superuser
    100000    3    udp6      ::.0.111               portmapper superuser
    100000    4    tcp       0.0.0.0.0.111          portmapper superuser
    100000    3    tcp       0.0.0.0.0.111          portmapper superuser
    100000    2    tcp       0.0.0.0.0.111          portmapper superuser
    100000    4    udp       0.0.0.0.0.111          portmapper superuser
    100000    3    udp       0.0.0.0.0.111          portmapper superuser
    100000    2    udp       0.0.0.0.0.111          portmapper superuser
    100000    4    local     /var/run/rpcbind.sock  portmapper superuser
    100000    3    local     /var/run/rpcbind.sock  portmapper superuser
    100005    1    udp       0.0.0.0.16.146         mountd     superuser
    100005    2    udp       0.0.0.0.16.146         mountd     superuser
    100005    3    udp       0.0.0.0.16.146         mountd     superuser
    100005    1    tcp       0.0.0.0.16.146         mountd     superuser
    100005    2    tcp       0.0.0.0.16.146         mountd     superuser
    100005    3    tcp       0.0.0.0.16.146         mountd     superuser
    100003    3    tcp       0.0.0.0.8.1            nfs        superuser

[root@cdh60 ~]# mkdir /hdfs_nfs_mount


root@cdh60 ~]# mount -t nfs -o vers=3,proto=tcp,nolock cdh60:/ /hdfs_nfs_mount
[root@cdh60 ~]# df -h /hdfs_nfs_mount
Filesystem               Size  Used Avail Use% Mounted on
cdh60:/                   69G  6.5G   63G  10% /hdfs_nfs_mount


Linux Permission Applies:

[root@cdh60 dsuser]# ls -ld /hdfs_nfs_mount/data/incoming/
drwxr-xr-x 3 dsuser 2584148964 96 Aug 19 12:17 /hdfs_nfs_mount/data/incoming/

[root@cdh60 dsuser]# cp employees.csv /hdfs_nfs_mount/data/incoming/
cp: cannot create regular file ‘/hdfs_nfs_mount/data/incoming/employees.csv’: Permission denied

Login as dsuser (owner of incoming folder)

Donghuas-MacBook-Air:pandas donghua$ ssh dsuser@cdh60
dsuser@cdh60's password: 
Last login: Sun Aug 19 09:24:50 2018 from 192.168.1.1

[dsuser@cdh60 ~]$ klist
Ticket cache: FILE:/tmp/krb5cc_1001
Default principal: dsuser@DBAGLOBE.COM

Valid starting       Expires              Service principal
08/19/2018 09:24:54  08/20/2018 09:24:54  krbtgt/DBAGLOBE.COM@DBAGLOBE.COM
    renew until 08/26/2018 09:24:54

[dsuser@cdh60 ~]$ cp employees.csv /hdfs_nfs_mount/data/incoming/

[dsuser@cdh60 ~]$ ls -l /hdfs_nfs_mount/data/incoming/employees.csv
-rw-r--r-- 1 dsuser 2584148964 59175 Aug 19 12:17 /hdfs_nfs_mount/data/incoming/employees.csv

[dsuser@cdh60 ~]$ hdfs dfs -ls /data/incoming/
Found 1 items
-rw-r--r--   1 dsuser supergroup      59175 2018-08-19 12:17 /data/incoming/employees.csv


[dsuser@cdh60 ~]$ hdfs dfs -cat /data/incoming/employees.csv|head -n 3
First Name,Gender,Start Date,Last Login Time,Salary,Bonus %,Senior Management,Team
Douglas,Male,8/6/1993,12:42 PM,97308,6.945,true,Marketing
Thomas,Male,3/31/1996,6:53 AM,61933,4.17,true,

[dsuser@cdh60 ~]$ cat /hdfs_nfs_mount/data/incoming/employees.csv |head -n3
First Name,Gender,Start Date,Last Login Time,Salary,Bonus %,Senior Management,Team
Douglas,Male,8/6/1993,12:42 PM,97308,6.945,true,Marketing
Thomas,Male,3/31/1996,6:53 AM,61933,4.17,true,

Login as root (act as normal nfs client user)

[root@cdh60 dsuser]# hdfs dfs -cat /data/incoming/employees.csv|head -n 3
18/08/19 12:26:56 WARN ipc.Client: Exception encountered while connecting to the server : org.apache.hadoop.security.AccessControlException: Client cannot authenticate via:[TOKEN, KERBEROS]
cat: Failed on local exception: java.io.IOException: org.apache.hadoop.security.AccessControlException: Client cannot authenticate via:[TOKEN, KERBEROS]; Host Details : local host is: "cdh60.dbaglobe.com/192.168.56.110"; destination host is: "cdh60.dbaglobe.com":8020; 

[root@cdh60 dsuser]# cat /hdfs_nfs_mount/data/incoming/employees.csv |head -n3
First Name,Gender,Start Date,Last Login Time,Salary,Bonus %,Senior Management,Team
Douglas,Male,8/6/1993,12:42 PM,97308,6.945,true,Marketing
Thomas,Male,3/31/1996,6:53 AM,61933,4.17,true,

How to enable PAM Authentication in Zeppelin

Step 1: comment out preconfigured user

/usr/hdp/current/zeppelin-server/conf/shiro.ini

#[users]
# List of users with their password allowed to access Zeppelin.
# To use a different strategy (LDAP / Database / ...) check the shiro doc at http://shiro.apache.org/configuration.html#Configuration-INISections
#admin = $shiro1$SHA-256$500000$p6Be9+t2hdUXJQj2D0b1fg==$bea5JIMqcVF3J6eNZGWQ/3eeDByn5iEZDuGsEip06+M=, admin
#user1 = $shiro1$SHA-256$500000$G2ymy/qmuZnGY6or4v2KfA==$v9fabqWgCNCgechtOUqAQenGDs0OSLP28q2wolPT4wU=, role1, role2
#user2 = $shiro1$SHA-256$500000$aHBgiuwSgAcP3Xt5mEzeFw==$KosBnN2BNKA9/KHBL0hnU/woJFl+xzJFj12NQ0fnjCU=, role3
#user3 = $shiro1$SHA-256$500000$nf0GzH10GbYVoxa7DOlOSw==$ov/IA5W8mRWPwvAoBjNYxg3udJK0EmrVMvFCwcr9eAs=, role2


Step 2: enable PAM


/usr/hdp/current/zeppelin-server/conf/shiro.ini

### A sample PAM configuration
pamRealm=org.apache.zeppelin.realm.PamRealm
pamRealm.service=sshd


Step 3: Grant access to /etc/shadow

[root@hdp30 bin]# setfacl -m user:zeppelin:r /etc/shadow
[root@hdp30 bin]# getfacl /etc/shadow
getfacl: Removing leading '/' from absolute path names
# file: etc/shadow
# owner: root
# group: root
user::---
user:zeppelin:r--
group::---
mask::r--
other::---

Step 4: Restart Zeppelin and login using os user donghua


==> /var/log/zeppelin/zeppelin-zeppelin-hdp30.log <==
 WARN [2018-08-05 20:04:43,756] ({qtp110992469-18} LoginRestApi.java[postLogin]:206) - {"status":"OK","message":"","body":{"principal":"donghua","ticket":"fa4817f4-c68a-4c0e-b61a-39295daa3062","roles":"[]"}}


Reference: https://community.hortonworks.com/content/supportkb/167636/how-to-enable-pam-authentication-in-zeppelin.html