HBase Master always Stop...

HBase Master always Stop...

  Monday, October 07, 2019    ataicha

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Use Case

HBase Master Process always ERROR and stop the services after several minutes and need to start manually.

Solution

NTP Server not sync... So need to check NTP at where HBase Master and RegionalServer has been installed. So i found one of server that installed Regional Server has been stop.

[root@hdpworker1 ~]# ntpstat
synchronised to NTP server (103.16.182.23) at stratum 5
   time correct to within 262 ms
   polling server every 1024 s 

[root@hdpworker2 ~]# ntpstat
synchronised to NTP server (103.16.182.23) at stratum 5
   time correct to within 257 ms
   polling server every 1024 s 

[root@hdpworker3 ~]# ntpstat
timeout 

[root@hdpworker4 ~]# ntpstat
synchronised to NTP server (103.16.182.23) at stratum 5
   time correct to within 264 ms
   polling server every 1024 s

So need to start it again and restart all services for Hbase.

Refer :

• https://docs.couchbase.com/server/current/install/synchronize-clocks-using-ntp.html
• https://www.cyberciti.biz/faq/rhel-fedora-centos-configure-ntp-client-server/

But it still failed after 30 minutes HBase Master has been started. 

So i procced to 2nd step... What the 2nd Step? 

Solve issue with stale WAL splits, by removing WAL's from hdfs location /apps/hbase/data/WALs/ and restart the HBase master and region services.

1. Make a temporary file other than /apps/hbase/data/WALs/  by this commands

su -hdfs 

hdfs dfs -mkdir /apps/hbase/data/tempWALs

2. Why i create temporary folder? Because easy if anything happen..  then move all file under /apps/hbase/data/WALs to this directory.

hdfs dfs -mkdir /apps/hbase/data/WALs/* /apps/hbase/data/tempWALs/

3. Then restart all services. Hopefully this will your right solution.

For me, this has solve my problem.

Refer :

• https://community.cloudera.com/t5/Support-Questions/HBase-master-fails-to-start/td-p/146453
• https://techtalks.tech/knowledge-base/clear-dead-region-servers-in-hbase/

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Configuring NameNode Heap Size

Configuring NameNode Heap Size

  Monday, February 11, 2019    ataicha

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Okay, so as my hadoop already reach more than 6 Milion files, the current setting is not suitable for running nameNode. So need toTotal Java Heap need to  increased to 6GB.

Details can refer this arcticle : https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.6.5/bk_command-line-installation/content/configuring-namenode-heap-size.html

NameNode heap size depends on many factors, such as the number of files, the number of blocks, and the load on the system. The following table provides recommendations for NameNode heap size configuration. These settings should work for typical Hadoop clusters in which the number of blocks is very close to the number of files (generally, the average ratio of number of blocks per file in a system is 1.1 to 1.2).
Some clusters might require further tweaking of the following settings. Also, it is generally better to set the total Java heap to a higher value.

​

Table 1.11. Recommended NameNode Heap Size Settings

Number of Files, in Millions	Total Java Heap (Xmx and Xms)	Young Generation Size (-XX:NewSize -XX:MaxNewSize)
< 1 million files	1126m	128m
1-5 million files	3379m	512m
5-10	5913m	768m
10-20	10982m	1280m
20-30	16332m	2048m
30-40	21401m	2560m
40-50	26752m	3072m
50-70	36889m	4352m
70-100	52659m	6144m
100-125	65612m	7680m
125-150	78566m	8960m
150-200	104473m	8960m

	Note
	Hortonworks recommends a maximum of 300 million files on the NameNode.

You should also set -XX:PermSize to 128m and -XX:MaxPermSize to 256m.
Following are the recommended settings for HADOOP_NAMENODE_OPTS in the hadoop-env.sh file (replacing the ##### placeholder for -XX:NewSize, -XX:MaxNewSize, -Xms, and -Xmx with the recommended values from the table):

-server -XX:ParallelGCThreads=8 -XX:+UseConcMarkSweepGC -XX:ErrorFile=/var/log/hadoop/$USER/hs_err_pid%p.log -XX:NewSize=##### -XX:MaxNewSize=##### -Xms##### -Xmx##### -XX:PermSize=128m -XX:MaxPermSize=256m -Xloggc:/var/log/hadoop/$USER/gc.log-`date +'%Y%m%d%H%M'` -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -Dhadoop.security.logger=INFO,DRFAS -Dhdfs.audit.logger=INFO,DRFAAUDIT ${HADOOP_NAMENODE_OPTS}

If the cluster uses a secondary NameNode, you should also set HADOOP_SECONDARYNAMENODE_OPTS to HADOOP_NAMENODE_OPTS in the hadoop-env.sh file:

HADOOP_SECONDARYNAMENODE_OPTS=$HADOOP_NAMENODE_OPTS

Another useful HADOOP_NAMENODE_OPTS setting is -XX:+HeapDumpOnOutOfMemoryError. This option specifies that a heap dump should be executed when an out-of-memory error occurs. You should also use -XX:HeapDumpPath to specify the location for the heap dump file:

-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=./etc/heapdump.hprof

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Bagaimana hendak transfer file dari Linux ke Window?

Bagaimana hendak transfer file dari Linux ke Window?

  Friday, February 08, 2019    ataicha

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Mungkin benda ini akan terjadi, yup memang terjadi pun. Hari ini ataicha nak share bagaimana cara hendak transfer file dari Linux ke Windows.

Biasa kita dengar PuTTY kan? Kita akan guna satu benda yang dinamakan pscp.

PSCP ni nama penuhnya PuTTY Secure Copy. Ia adalah satu aplikasi yang mampu membolehkan transfer files dari beberapa sistem operasi yang berlainan dengan menggunakan command window di sistem operasi Windows. Ianya adalah percuma.

Untuk menggunakan ini, digalakkan install PuTTY sekali laa ye..

Kalau belum ada, boleh install dari website ini (Klik sini)

Ok kalau dah install, jangan lupa letak kat mana ye.. biasa ataicha setkan install ke C:\Program Files\PuTTY

Ingat tau kat mana korang install... sebab nanti nak guna kena tahu kat mana korang install..

Step 1 : Buka Command Prompt korang.
Pergi ke Start Menu dan masukkan cmd.exe kat Search Field. Klik Enter.

Step 2 : ok tukar ke directory yang mana korang letak file tu.. cam ataicha set kat C:\Program Files\PuTTY so kena taip

cd c:\Program Files\PuTTY

ok dah kan?

so nak test jalan ke tak korang taip pscp plak..

pscp

 resultnya akan terpapar macam ini








Kalau keluar macam ini, pscp korang jalan ok laa tu..

Sebab isu privacy, so ataicha tak leh nak snapshot real situation laa ye..

ni example untuk rujukan

• sample-dir-linux : /home/ataicha
• sample-dir-windows : c:/ataicha/test
• sample-linux-username : naufal
• sample-linux-server-ipaddress : 10.20.30.40

katakan ataicha nak copy nama file ataicharesume.txt dari server linux ke labtop ataicha sekarang.

PERHATIAN : ops lupa pastikan server linux korang dah allow untuk ssh access tau. tak allowed memang tak jalan..

FORMAT UNTUK TRANSFER:

pscp.exe linux-username@linux-server-ipaddress: [source-DIR-inLinux] [destination-DIR-inWin]

kalau ikut example ataicha share kat atas tu.. korang kena taip cam ni

pscp.exe naufal@10.20.30.40:/home/ataicha/ataicharesume.txt c:/ataicha/test

dan nanti dia akan prompt untuk masukkan password linux ye..

maksud atas tu atas tu, ataicha copy files ataicharesume.txt yang berada di folder /home/ataicha di server linux ke c:/ataicha/test di windows.

PERHATIAN : pastikan folder wujud ye. sebab command ni tak leh nak create folder auto tau.

Semoga membantu anda semua.

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Removing Line Breaks or New Line Characters in a SQL Query

Removing Line Breaks or New Line Characters in a SQL Query

  Thursday, April 19, 2018    ataicha

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So ni solution untuk remove atau replace line breaks or new line characters dalam SQL Query.

SQL Query : SELECT REPLACE( REPLACE (`FIELDNAME`, CHAR(13), '  '), CHAR(10), '  ') AS `remarks` from TABLENAME;

Yang mana REPLACE ni akan replace CHAR(13) dan CHAR(10) dengan ' '.

- For ataicha REFERENCE PURPOSE.

REFERENCES : http://blogs.catapultsystems.com/rhutton/archive/2013/10/03/removing-line-breaks-or-new-line-characters-in-a-sql-query/

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[IT Tips] - Reset or recover forgotten Admin Password for Exinda

[IT Tips] - Reset or recover forgotten Admin Password for Exinda

  Wednesday, September 18, 2013    ataicha

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I have misplaced/forgotten my password to gain access to the Exinda device. Is there a way to recover a lost or forgotten password?

If the administrator of a system running firmware v5++ forgets the password of the user 'admin', the following method can be used to reset the password to the default password.

Default admin credentials are:

username: admin

password: exinda

The basic procedure is to boot the system to single user and execute a script to reset the 'admin' password in the active database. If any database corruption is suspected, the script resets the system database to an initialized default one. The 'admin' password is not set in such a database. A system booted to single user mode does not require a privileged user password.

First, the system must be rebooted or power cycled. It is assumed the person following this procedure is able to access the system's console and can see the entire boot process (this is either over a serial console or the system's direct console).

Step1: Press the down key when it says "Boot loading stage 2"and select the image to boot into. Once the image is selected (in this case 0) then press “e” to enter the edit command mode. This will give the user the ability to change the commands options that are part of the boot process.

     Boot Menu

---------------------------------------

0: exinda-5.4.0.13350 (i386) 2010/03/31

1: exinda-5.4.0.13350 (i386) 2010/03/31

2: memtest86+ v1.70

---------------------------------------

     Use the up and down keys to select which entry is highlighted.

     Press enter to boot the selected image. 'e' to edit the 

     commands before booting. 'a' to modify the kernel arguments

     before booting or 'c' for a command-line.

  Highlighted entry is 0:

Step2: Now use the arrow key and select 1 (for kernel.......) and type “e” again

     Boot Menu

---------------------------------------

0: root (hd0,1)

1: kernel /vmlinuz ro root=/dev/sda5    img_id=1 quiet loglevel=4 panic=10 console=tty0

console=ttyS0.9600n8

---------------------------------------

     Use the up and down keys to select which entry is highlighted.

     Press 'b' to boot, 'e' to edit the selected command in the 

     boot sequence, 'c' for a command-line. 'o' to open a new line

     after ('0' for before) the selected line. 'd' to remove the 

     selected line or escape to go back to the main menu.

  Highlighted entry is 1:

Step3: On the next screen after entering 'e' go to the end of the line and the text 'single' should be appended to the end of this line.

Note: The '<' indicates that a portion of the command line is not seen.  The arrow keys allow the user to navigate the command line to the very end so that above step 2 can be done as below:

Step4: On the next screen select option 1 (kernel.....) and type "b"  to resume booting the selected image.

    Boot Menu

---------------------------------------

0: root (hd0,1)

1: kernel /vmlinuz ro root=/dev/sda5    img_id=1 quiet loglevel=4 panic=10 console=tty0

console=ttyS0.9600n8 single

---------------------------------------

     Use the up and down keys to select which entry is highlighted.

     Press 'b' to boot, 'e' to edit the selected command in the 

     boot sequence, 'c' for a command-line. 'o' to open a new line

     after ('0' for before) the selected line. 'd' to remove the 

     selected line or escape to go back to the main menu.

  Highlighted entry is 1:

Step5: After more boot messages a 'root' user prompt should be displayed as below:

 resh-3.2#

Type here: “/sbin/resetpw.sh” as below:

resh-3.2#/sbin/resetpw.sh

Step6: If successful, the 'admin' password will now be reset to the default password. The system can now be restarted by issuing the command 'reboot' at the command prompt:

sh-3.2# reboot

 

Source : http://support.exinda.com/topic/i-have-misplaced-forgotten-my-password-to-gain-access-to-the-exinda-device-is-there-a-way-to-recover-a-lost-or-forgotten-password

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[IT Tips] - Resetting a lost Fortigate Admin Password

[IT Tips] - Resetting a lost Fortigate Admin Password

  Wednesday, September 18, 2013    ataicha

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If you have lost the admin password for a Fortigate you can reset it if you have physical access to the box.

• Connect the console cable to the Fortigate and fire up your favorite terminal emulator

• Reboot the firewall unit.

• At the console login prompt, type in "maintainer" as the userid.

• Type in bcpbFGTxxxxxxxxxxxxx as the password. xxxxxxxxxxxxx will be the S/N of the Fortigate. The serial number is case sensitive so for example you should use FGT60B, not FGT60b.

• After logging in, change the admin password:

config system admin
edit admin
set password
next
end

Heads up: You have to type the userid and password within a few seconds of the login prompt first appearing. If you take too much time you should reboot the firewall again.

References : http://firewallguru.blogspot.com/2009/08/resetting-lost-fortigate-admin-password.html

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