Value '0000-00-00' can not be represented as java.sql.Timestamp IN PENTAHO (PDI)

In Kettle (Pentaho Data Integration), when you use a "Table Input" component, you have to create a database connection.
In the database connection form, fill the fields of your mysql database, and test it.
If successfull, go to Options (left tab)
In the right tab, below defaultFetchSize and useCursorFetch, add zeroDateTimeBehavior and it's value convertToNull

Hope this helps !

How do you create a read only user in postgresql

Grant usage/select to a single table

If you only grant CONNECT to a database, the user can connect but has no other privileges. You have to grant USAGE on namespaces (schemas) and SELECT on tables and views individually like so:

GRANT CONNECT ON DATABASE postgres TO user1; GRANT USAGE ON SCHEMA public TO user1; GRANT SELECT ON table01 TO user1;

Multiple tables/views

you can grant permissions on all tables/views/etc in the schema using a single command rather than having to type them one by one:

GRANT SELECT ON ALL TABLES IN SCHEMA public TO user1;

This only affects tables that have already been created. More powerfully, you can automatically have default roles assigned to new objects in future:

ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO user1;

Or you can create role before creating a user, like i usually do

-- Create a group CREATE ROLE read_access_dwh; -- Grant access to existing tables GRANT USAGE ON SCHEMA dwh TO read_access_dwh; GRANT SELECT ON ALL TABLES IN SCHEMA dwh TO read_access_dwh; -- Grant access to future tables ALTER DEFAULT PRIVILEGES IN SCHEMA dwhp GRANT SELECT ON TABLES TO read_access_dwh; -- Create a final user with password CREATE USER report_dwh WITH PASSWORD 'yourpassword'; GRANT CONNECT ON DATABASE postgres TO report_dwh; GRANT read_access_dwh TO report_dwh;

Postgres Command Line Connection from shell

This article describes how to connect to a PostgreSQL database from the shell using the psql program.
You can use the psql program as a quick and easy way to access your databases directly.


PSQL Commands: Connect to PostgreSQL from shell

To connect to PostgreSQL cli:

1. login to the server with SSH where the postgres database is located.


2. At the shell, type the following command. Replace DBNAME with the name of the database, and USERNAME with the database username:
   
   

   psql DBNAME USERNAME



3. At the Password prompt, type the database user's password. When you type the correct password, the psql prompt appears.


4. After you access a PostgreSQL database, you can run SQL queries and more. Here are some common psql commands:


• To view help for psql commands, type \?.
• To view help for SQL commands, type \h.
• To view information about the current database connection, type \conninfo.
• To list the database's tables and their respective owners, type \dt.
• To list all of the tables, views, and sequences in the database, type \z.
• To exit the psql program, type \q.

How to install SubversionEdge or CollabNet SVN on Centos

For any company in IT Department, versioning is a darn important part of the development process.

Software versioning is important because:

• It maintains the history of your code and the sequence in which changes were made
• It maintains the latest copy of your code in case your computer crashes
• It helps manage code properly when collaborating with other developers

You’ll understand the importance right away, when a developer you’re working with makes and edit that can’t be reverted or when a client accidentally deletes a file.
Trust me that happens.

In this article, I’m going to talk about installing this very software on Centos


Installing SubversionEdge

because we will install CSVN in user mode, for that we must create CSVN user first.

[root@localhost ~]# adduser csvn [root@localhost ~]# passwd csvn Changing password for user csvn. New password: Retype new password: passwd: all authentication tokens updated successfully.

Step #1 The Prerequisites

So, we start with the prerequisites. The prerequisite for SubversionEdge is Java. Hence, to begin with, we’ll have to install Java.
Now, if you’re not sure if Java is already installed, you can fire the below command to check the same:

[root@localhost ~]# java -version openjdk version "1.8.0_121" OpenJDK Runtime Environment (build 1.8.0_121-b13) OpenJDK 64-Bit Server VM (build 25.121-b13, mixed mode)

If Java is installed the Java version should be displayed. if java is not installed on your system, you can install java in the following url:


Step #2 Installing CollabNet SVN

Download the latest version of Subversion Edge from CollabNet. It should be a tar.gz file.

Then, use the below commands to install the software. Do remember to replace CollabNetSubversionEdge-5.2.4_linux-x86_64.tar.gz with the tar.gz file you’ve downloaded from CollabNet. and put the downloaded file into the folder /home

[root@localhost ~]# cd /home [root@localhost home]# [root@localhost home]# gzip -d CollabNetSubversionEdge-5.2.4_linux-x86_64.tar.gz [root@localhost home]# tar xf CollabNetSubversionEdge-5.2.4_linux-x86_64.tar [root@localhost home]# cd /home/csvn/bin/ [root@localhost bin]# ./csvn install Detected RHEL or Fedora: Installing the CSVN Console daemon.. Setting RUN_AS_USER to: 'root'. Please edit '../data/conf/csvn.conf' if this needs to be adjusted Setting JAVA_HOME to: ''. Please edit '../data/conf/csvn.conf' if this needs to be adjusted. [root@localhost bin]# ./csvn-httpd install Detected RHEL or Fedora:  Installing the Subversion Edge Apache Server daemon.. [root@localhost bin]# cd /home/ [root@localhost home]# chown csvn:csvn csvn/ -Rf

login as csvn user and edit file csvn.conf

[csvn@localhost ~]$ vi data/conf/csvn.conf

Setting RUN_AS_USER to: csvn

and back to root account again

CollabNet SVN should now be installed. All we need to do, is start their console and start using the application.
To start their console, fire the command

[root@localhost ~]# service csvn start Starting CSVN Console... ... CSVN Console started Waiting for application to initialize (this may take a minute)............................... CSVN Console is ready at http://localhost:3343/csvn

Once this command runs successfully, you can view CollabNet SVN at work by heading over to http://localhost:3343/csvn
That’s it! Hope you’ve got the service up and running. and you can adjust the server settings to the existing conditions


Good luck managing your repositories!

Install Java on Centos

INSTALL JAVA 

Download the latest JAVA  from  here or use the following command to download JAVA JDK

# wget --no-cookies \ --no-check-certificate \ --header "Cookie: oraclelicense=accept-securebackup-cookie" \ "https://download.oracle.com/otn-pub/java/jdk/8u201-b09/42970487e3af4f5aa5bca3f542482c60/jdk-8u201-linux-x64.rpm" \ -O /tmp/jdk-8u201-linux-x64.rpm

once the JAVA package has been downloaded, install it using rpm as follows:

# rpm -Uvh /tmp/jdk-8u201-linux-x64.rpm

CONFIGURE JAVA

configure the newly installed JAVA package using alternatives as in:

# alternatives --install /usr/bin/java java /usr/java/jdk1.8.0_201-amd64/jre/bin/java 20000 # alternatives --install /usr/bin/jar jar /usr/java/jdk1.8.0_201-amd64/bin/jar 20000 # alternatives --install /usr/bin/javac javac /usr/java/jdk1.8.0_201-amd64/bin/javac 20000 # alternatives --install /usr/bin/javaws javaws /usr/java/jdk1.8.0_201-amd64/jre/bin/javaws 20000 # alternatives --set java /usr/java/jdk1.8.0_201-amd64/jre/bin/java # alternatives --set javaws /usr/java/jdk1.8.0_201-amd64/jre/bin/javaws # alternatives --set javac /usr/java/jdk1.8.0_201-amd64/bin/javac # alternatives --set jar /usr/java/jdk1.8.0_201-amd64/bin/jar

check the JAVA version running on your system:

# java -version

Fix ORA-03113: end-of-file on communication channel

One day my server died suddenly due to a power problem, this caused a problem with my Oracle database,
ORA-03113: end-of-file on communication channel.

[oracle@localhost ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Fri Aug 16 14:22:01 2019 Copyright (c) 1982, 2013, Oracle.  All rights reserved. Connected to an idle instance. SQL> startup ORACLE instance started. Total System Global Area 4993982464 bytes Fixed Size            2261808 bytes Variable Size         1006636240 bytes Database Buffers     3976200192 bytes Redo Buffers            8884224 bytes Database mounted. ORA-03113: end-of-file on communication channel Process ID: 4903 Session ID: 237 Serial number: 26032

After searching for ways to repair the server, I finally found the solution. Here are the steps:

[oracle@localhost ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Fri Aug 16 14:22:01 2019 Copyright (c) 1982, 2013, Oracle.  All rights reserved. Connected to an idle instance. SQL> startup mount; ORACLE instance started. Total System Global Area 4993982464 bytes Fixed Size            2261808 bytes Variable Size         1006636240 bytes Database Buffers     3976200192 bytes Redo Buffers            8884224 bytes Database mounted. SQL> SELECT GROUP# FROM V$LOG;     GROUP# ----------      1      3      2 SQL> alter database clear unarchived logfile group 1; Database altered. SQL> alter database clear unarchived logfile group 2; Database altered. SQL> alter database clear unarchived logfile group 3; Database altered. SQL> shutdown immediate; ORA-01109: database not open Database dismounted. ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area 4993982464 bytes Fixed Size            2261808 bytes Variable Size         1006636240 bytes Database Buffers     3976200192 bytes Redo Buffers            8884224 bytes Database mounted. Database opened. SQL>

If this method still fails, then there is a second method, which is as follows
Now, go into sqlplus without opening the database, just mounting it.

[oracle@localhost ~]$ sqlplus /nolog SQL*Plus: Release 11.2.0.4.0 Production on Fri Aug 16 14:45:09 2019 Copyright (c) 1982, 2013, Oracle.  All rights reserved. SQL> connect / as sysdba Connected to an idle instance. SQL> startup mount ORACLE instance started. Total System Global Area 4993982464 bytes Fixed Size            2261808 bytes Variable Size         1006636240 bytes Database Buffers     3976200192 bytes Redo Buffers            8884224 bytes Database mounted. SQL>

Now, you can increase your current db_recovery_file_dest_size, increased to 100G in my case:

SQL> alter system set db_recovery_file_dest_size = 100G scope=both; System altered.

Now, you can shutdown and startup again and that previous error should be gone. The proper fix is to get rid of the recovery files. You do that using RMAN

[oracle@localhost ~]$ rman target / Recovery Manager: Release 11.2.0.4.0 - Production on Fri Aug 16 14:49:39 2019 Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved. connected to target database: DB11G (DBID=432722608, not open) RMAN> backup archivelog all delete input; Starting backup at 16-AUG-19 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=156 device type=DISK specification does not match any archived log in the repository backup cancelled because there are no files to backup Finished backup at 16-AUG-19 RMAN> exit Recovery Manager complete.

Wait a long time and your archivelog (that was using up all that space) will be gone. So, you can shutdown/startup your database and be back in business.

[oracle@jktdi009 ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Fri Aug 16 14:52:16 2019 Copyright (c) 1982, 2013, Oracle.  All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> shutdown immediate; ORA-01109: database not open Database dismounted. ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area 4993982464 bytes Fixed Size            2261808 bytes Variable Size         1006636240 bytes Database Buffers     3976200192 bytes Redo Buffers            8884224 bytes Database mounted. Database opened. SQL>

vsftpd configuration of the ftp server in my company

Just to remember the vsftpd configuration of the ftp server in my company

The following configuration is on centos 6

anonymous_enable=NO local_enable=YES write_enable=YES local_umask=022 dirmessage_enable=YES xferlog_enable=YES xferlog_file=/var/log/vsftpd.log log_ftp_protocol=YES connect_from_port_20=YES xferlog_std_format=YES nopriv_user=ftp pam_service_name=vsftpd listen=YES tcp_wrappers=YES pasv_enable=YES pasv_max_port=1200 pasv_min_port=1026 port_enable=YES ascii_upload_enable=YES ascii_download_enable=YES ftpd_banner=Welcome to Private FTP Server. secure_chroot_dir=/home one_process_model=NO chroot_local_user=YES allow_writeable_chroot=YES guest_enable=NO use_localtime=YES #rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem #rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key seccomp_sandbox=NO

This works since 2011 after upgrading from Centos 5

If there are ORA-01092 and ORA-30012 errors together

Errors like this

ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-30012: undo tablespace 'UNDOTBS01' does not exist or of wrong type

if there are ORA-01092 and ORA-30012 errors together, here's how to resolve them

[oracle@localhost ~]$ sqlplus /nolog SQL*Plus: Release 11.2.0.3.0 Production on Mon Aug 5 10:23:32 2019 Copyright (c) 1982, 2011, Oracle.  All rights reserved. SQL> connect sys as sysdba Enter password: Connected to an idle instance. SQL>

SQL> startup mount ORACLE instance started. Total System Global Area 535662592 bytes Fixed Size 1375792 bytes Variable Size 331350480 bytes Database Buffers 197132288 bytes Redo Buffers 5804032 bytes Database mounted.

SQL> select * from v$tablespace; TS# NAME INC BIG FLA ENC ---------- ------------------------------ --- --- --- --- 0 SYSTEM YES NO YES 1 SYSAUX YES NO YES 4 USERS YES NO YES 3 TEMP NO NO YES 6 EXAMPLE YES NO YES 9 RCRMAN YES NO YES 10 USERS_TBS YES NO YES 5 UNDOTBS2 YES NO YES 19 TESTTBS YES NO YES 14 TESTTB YES NO YES TS# NAME INC BIG FLA ENC ---------- ------------------------------ --- --- --- --- 15 TESTDB YES NO YES 12 rows selected.

SQL> create pfile='/oracle/product/11.2.0/db_1/dbs/initbckorcl.ora' from spfile; File created.

SQL> shutdown immediate ORA-01109: database not open Database dismounted. ORACLE instance shut down.

Edit Pfile UNDO_TABLESPACE PARAMETER

ORCL.undo_tablespace='UNDOTBS01' orcl.undo_tablespace='UNDOTBS01' *.undo_tablespace='UNDOTBS02'

Change like this

ORCL.undo_tablespace='UNDOTBS02' orcl.undo_tablespace='UNDOTBS02' *.undo_tablespace='UNDOTBS02'

Startup with new pfile

SQL> startup pfile='/oracle/product/11.2.0/db_1/dbs/initbckorcl.ora'; ORACLE instance started. Total System Global Area 535662592 bytes Fixed Size 1375792 bytes Variable Size 331350480 bytes Database Buffers 197132288 bytes Redo Buffers 5804032 bytes Database mounted. Database opened. SQL>

SQL> create spfile from pfile; File created. SQL> create spfile from pfile='/oracle/product/11.2.0/db_1/dbs/initbckorcl.ora'; File created.

SQL> shutdown immediate Database closed. Database dismounted. ORACLE instance shut down.

SQL> startup ORACLE instance started. Total System Global Area 535662592 bytes Fixed Size 1375792 bytes Variable Size 331350480 bytes Database Buffers 197132288 bytes Redo Buffers 5804032 bytes Database mounted. Database opened.

SQL> show parameter undo; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ undo_management string AUTO undo_retention integer 900 undo_tablespace string UNDOTBS2

How to Install Nginx on CentOS 7

How to Install Nginx on CentOS 7

Nginx [engine x] is free and open source high-performance web server. It also acts as a reverse proxy server, as well as. This page shows how to install Nginx server on a CentOS 7 or RHEL 7 and configure a static web site.

In this article, we will explain how to install, configure and manage Nginx HTTP web server on a CentOS 7 or RHEL 7 server using command line.


Install Nginx Web Server

1. First update the system software packages to the latest version.



# yum -y update



2. Next, install Nginx HTTP server from the EPEL repository using the YUM package manager, or if you have not installed the epel repository you can install the nginx repository.

Configure EPEL repo



# yum install epel-release


Configure Nginx repo for CentOS 7 & RHEL (Red Hat Enterprise Linux) version 7.x



# vi /etc/yum.repos.d/nginx.repo


Append following for CentOS 7.x:



[nginx] name=nginx repo baseurl=http://nginx.org/packages/mainline/centos/7/$basearch/ gpgcheck=0 enabled=1


Append following for RHEL (Red Hat Enterprise Linux) version 7.x:



[nginx] name=nginx repo baseurl=http://nginx.org/packages/mainline/rhel/7/$basearch/ gpgcheck=0 enabled=1


Next, install Nginx



# yum install nginx

Manage Nginx HTTP Server

1. Once Nginx web server installed, you can start it first time and enable it to start automatically at system boot.



# systemctl start nginx # systemctl enable nginx # systemctl status nginx

Configure firewalld to Allow Nginx Traffic

1. By default, CentOS 7 and RHEL 7 built-in firewall is set to block Nginx traffic. To allow web traffic on Nginx, update the system firewall rules to permit inbound packets on HTTP and HTTPS using the commands below.



# firewall-cmd --zone=public --permanent --add-service=http # firewall-cmd --zone=public --permanent --add-service=https # firewall-cmd --reload

Test Nginx Server on CentOS 7 and RHEL 7

1. Now you can verify Nginx server by going to the following URL, a default nginx page will be shown.



http://SERVER_DOMAIN_NAME_OR_IP


You can also use the curl command to get same info using the cli:



$ curl -I http://10.21.136.13 $ curl http://10.21.136.13

Nginx Important Files and Directories

• The default server root directory (top level directory containing configuration files): /etc/nginx.
• The main Nginx configuration file: /etc/nginx/nginx.conf.
• Server block (virtual hosts) configurations can be added in: /etc/nginx/conf.d.
• The default server document root directory (contains web files): /usr/share/nginx/html.

Changing DNS Search Order

 

/etc/nsswitch.conf

Open /etc/nsswitch.conf file using text editor:

# vi /etc/nsswitch.conf

Look for hosts:

hosts: files dns mdns4

Set above order as per your requirement. Close and save the file.

host.conf – resolver configuration file

The file /etc/host.conf contains configuration information specific to the resolver library. It should contain one configuration keyword per line, followed by appropriate configuration information.

Open /etc/host.conf file

# vi /etc/host.conf

Find order line which specifies how host lookups are to be performed. It should be followed by one or more lookup methods, separated by commas. Valid methods are bind (dns server), hosts (/etc/hosts file), and nis (old method).

order hosts,bind

Save and close the file.

conclusion

 

The file /etc/nsswitch.conf will let you reconfigure the order of the name resolution. By default, the host file is the first, then the configured DNS. There could be more options.

The file /etc/hosts only lists IP addresses and hostnames (multiple names for one IP if you want) The file /etc/resolv.conf will list the default search domains, and will also list in sequence the name servers to use.

How to monitor MySQL using Nagios

How to configuring Nagios to monitor your MySQL server. Before we begin, there are a few prerequisites that you have to fulfill


Prerequisites

1. Operating System - CentOS.


2. Nagios Core - Installed and configured.


3. Nagios Plugins should be installed.


4. MySQL server(or MariaDB) should be installed on your server.

MySQL User Creation

1. Log in to your MySQL server with the following command.



# mysql -u root -p



2. Type in the following commands.



mysql> CREATE USER 'nagios'@'localhost' IDENTIFIED BY 'nagiospasswd'; mysql> GRANT ALL PRIVILEGES ON *.* TO 'nagios'@'localhost'; mysql> CREATE USER 'nagios'@'%' IDENTIFIED BY 'nagiospasswd'; mysql> GRANT ALL PRIVILEGES ON *.* TO 'nagios'@'%'; mysql> flush privileges;

These commands create a user "nagios" that can be used by local host as well as remotely. We have also granted all privileges to the user.


Install of the perl-modules DBI and DBD::mysql

Log in to nagios server use the following command to install perl-modules DBI and DBD::mysql

# yum -y install perl-DBI # yum -y install "perl(DBD::mysql)"

MySQL Plugin Installation

1. Run the following command to download the "check_mysql_health-2.2.2.tar.gz" package.



# wget https://labs.consol.de/assets/downloads/nagios/check_mysql_health-2.2.2.tar.gz



2. Extract the downloaded package.



# tar -zxvf check_mysql_health-2.2.2.tar.gz



3. Change into the check_mysql_health-2.2.2 directory.



# cd check_mysql_health-2.2.2



4. Run the following commands to configure and install the plugin.



# ./configure --prefix=/usr/local/nagios --with-nagios-user=nagios --with-nagios-group=nagios --with-perl=/usr/bin/perl # make # make install

Nagios Configuration for MySQL Monitoring

1. "check_mysql_health" Command Definition

The following file contains all the commands pertaining to Nagios. Open it in any text editor of your choice("vi" in this case).



# vi /usr/local/nagios/etc/objects/commands.cfg


Edit the file and add the "check_mysql_health" command block.



define command{ command_name check_mysql_health command_line $USER1$/check_mysql_health -H $ARG1$ --username $ARG2$ --password $ARG3$ --port $ARG4$ --mode $ARG5$ }



2. "check_mysql_health" Service Definition

Open the file "hosttomonitor.cfg" to add the service definition to the host that will be monitored.



# vi /usr/local/nagios/etc/servers/hosttomonitor.cfg


Add the following service blocks of Connection-time, io thread and sql thread. This will perform different tasks.



define service{ use local-service host_name hosttomonitor service_description MySQL connection-time check_command check_mysql_health!192.168.30.10!nagios!nagiospasswd!3306!connection-time! } define service{ use local-service host_name hosttomonitor service_description MySQL slave-io-running check_command check_mysql_health!192.168.30.10!nagios!nagiospasswd!3306!slave-io-running! } define service{ use local-service host_name hosttomonitor service_description MySQL slave-sql-running check_command check_mysql_health!192.168.30.10!nagios!nagiospasswd!3306!slave-sql-running! }



3. Restart the Nagios server.



# service nagios restart

You can configure other MySQL services as well whose information can be found on the website.

https://labs.consol.de/nagios/check_mysql_health/index.html

How to Install Nagios Plugins in CentOS

Prerequisites - Common

These are the common set of packages required for compiling most of the plugins. SNMP and required modules are included here are they are one of the most common types of network monitoring.

CentOS 6.x / 7.x

yum install -y gcc glibc glibc-common make gettext automake autoconf wget openssl-devel net-snmp net-snmp-utils epel-release yum install -y perl-Net-SNMP

Download latest nagios-plugins source and install using following commands

cd /opt wget http://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz tar xzf nagios-plugins-2.2.1.tar.gz cd nagios-plugins-2.2.1

Now compile and install nagios plugins

./configure --with-nagios-user=nagios --with-nagios-group=nagios make make install

Setup the nagios user:

useradd nagios passwd nagios

Plugin Installation Location

The plugins will now be located in /usr/local/nagios/libexec/.

How to Install - Oracle Plugin check_oracle_health (CentOS 6)

Prerequisites

Oracle software

The Oracle database server or instant client must be up and running.

CentOS packages

yum -y install cpan sharutils

Perl packages

Find out the absolute path of ORACLE_HOME and set the Oracle environment.
This is required for the installation of DBD::Oracle.

if Oracle 11gR2 server installated

export ORACLE_HOME=/u01/app/oracle/product/11.2.0/db_1 export LD_LIBRARY_PATH=$ORACLE_HOME/lib

if Oracle Instantclient installated

export ORACLE_HOME=/usr/lib/oracle/11.2/client64 export LD_LIBRARY_PATH=$ORACLE_HOME/lib

Install Perl DBD::Oracle module

wget http://www.cpan.org/modules/by-module/DBD/DBD-Oracle-1.74.tar.gz tar zxvf DBD-Oracle-1.74.tar.gz cd DBD-Oracle-1.74 perl Makefile.PL -l make && make test make install

Download and install the check_oracle_health plugin

Check for the latest version at http://labs.consol.de/lang/en/nagios/check_oracle_health/, scroll down to "Download".

cd /tmp wget https://labs.consol.de/assets/downloads/nagios/check_oracle_health-3.1.0.3.tar.gz tar xzf check_oracle_health-3.1.0.3.tar.gz cd /tmp/check_oracle_health-* ./configure make make install cp /usr/local/nagios/libexec/check_oracle_health /usr/lib64/nagios/plugins/

Set up the Oracle user "nagios" in target server

# as root: su - oracle sqlplus / as sysdba CREATE USER nagios IDENTIFIED BY oradbmon; GRANT CREATE SESSION TO nagios; GRANT SELECT any dictionary TO nagios; GRANT SELECT ON V_$SYSSTAT TO nagios; GRANT SELECT ON V_$INSTANCE TO nagios; GRANT SELECT ON V_$LOG TO nagios; GRANT SELECT ON SYS.DBA_DATA_FILES TO nagios; GRANT SELECT ON SYS.DBA_FREE_SPACE TO nagios; exit # leave SQL*Plus exit # back to root

Test locally

Please replace the path to ORACLE_HOME and the connect string as appropriate. In the following example,
the connect string refers to the alias in $ORACLE_HOME/network/admin/tnsnames.ora if your install server version
if you install instantclient connect string refers to the alias in /etc/tnsnames.ora

/usr/local/nagios/libexec/check_oracle_health --connect XE --user nagios --password oradbmon --environment ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe --mode tablespace-usage

Now you have to configure the check command in nagios. For the command to work, it needs to have the oracle client paths added to the environment variables – ORACLE_HOME, LD_LIBRARY_PATH,PATH. To avoid all sorts of issues in passing environment variables in nagios and altering the startup script of nagios to set them (as described on the author’s site), just pass the variables directly in the command. The latest version of check_oracle_health allows that.

Define command in /usr/local/nagios/etc/objects/command.cfg

vi /usr/local/nagios/etc/objects/command.cfg

# Oracle Database check health command # check_oracle_health    !  SID  !  USER  !  Pass  !  Warn  !  crit  !  mode define command {         command_name check_oracle_health         command_line $USER1$/check_oracle_health --environment PATH=$PATH:$ORACLE_HOME/bin --environment LD_LIBRARY_PATH=$ORACLE_HOME/lib --connect $ARG1$ --user $ARG2$ --password $ARG3$ --mode $ARG4$         } # Oracle Check Tablespace per name # check_oracle_health_tbs_name    !  SID  !  USER  !  Pass  !  Warn  !  crit  !  mode  ! tbs_name define command {         command_name check_oracle_health_tbs_name         command_line $USER1$/check_oracle_health --environment PATH=$PATH:$ORACLE_HOME/bin --environment LD_LIBRARY_PATH=$ORACLE_HOME/lib --connect $ARG1$ --user $ARG2$ --password $ARG3$ --mode $ARG4$ --name $ARG5$         }

Define service in /usr/local/nagios/etc/servers/oracledbtest.cfg

define host{ use                                     linux-server host_name                               oracledbtest alias                                   oracledbtest address                                 192.168.xx.yy max_check_attempts                      5 check_period                            24x7 notification_interval                   30 notification_period                     24x7 } ### Change last argument to the different modes ### tns-ping , process-usage , sga-shared-pool-free define service {         use                             local-service         host_name                       oracledbtest         service_description             Oracle Connection Time         check_command                   check_oracle_health!XE!nagios!oradbmon!connection-time         notifications_enabled           1 } define service {         use                             local-service         host_name                       oracledbtest         service_description             Oracle Connected Users         check_command                   check_oracle_health!XE!nagios!oradbmon!connected-users         notifications_enabled           1 } ### Change last argument to the different tablespace ### users, undotbs define service {         use                             local-service         host_name                       oracledbtest         service_description             Oracle Tablespace Usage Users         check_command                   check_oracle_health_tbs_name!XE!nagios!oradbmon!tablespace-usage!users         notifications_enabled           1 }

You can add all the modes you want. You can manually test the command like so. It’s very important that the ORACLE_HOME and other variables are set. They can be passed to the command directly, this way you don’t need to modify your nagios startup script to set the vars in the nagios user enviornment.

Install Oracle Instant Client on Linux CentOS

The installation of an Oracle client on a server is always a tedious task and although you have done it many times, there are always things to review.

In this case we are going to install an Oracle InstantClient of version 11 for the CentOS operating system.

As we also want to be able to compile applications that will be used by Oracle libraries, we will also have to install the header files.


Download installation packages

The installation files can be found at this URL:

https://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html

The client version to be used is 11.2.0.4.0

The packages to download are:

oracle-instantclient11.2-basic-11.2.0.4.0–1.x86_64.rpm oracle-instantclient11.2-devel-11.2.0.4.0–1.x86_64.rpm oracle-instantclient11.2-sqlplus-11.2.0.4.0–1.x86_64.rpm

The package with sqlplus is only needed to check that the installation was correct


Installing the RPM files

We proceed to the installation of previously downloaded packages

$ sudo yum localinstall -y oracle-instantclient11.2-basic-11.2.0.4.0–1.x86_64.rpm $ sudo yum localinstall -y oracle-instantclient11.2-devel-11.2.0.4.0-1.x86_64.rpm $ sudo yum localinstall -y oracle-instantclient11.2-sqlplus-11.2.0.4.0-1.x86_64.rpm

Environment Variables

We will need to define some environment variables for the Oracle client to work correctly

$ export ORACLE_HOME=/usr/lib/oracle/11.2/client64 $ export TNS_ADMIN=$ORACLE_HOME/network/admin $ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME/lib $ export PATH=$PATH:$ORACLE_HOME/bin

To be able to work with the tnsnames.ora file, we will have to copy it to the directory defined in the environment variable

$ sudo mkdir -p /usr/lib/oracle/11.2/client64/network/admin

Create new /usr/lib/oracle/11.2/client64/network/admin/tnsnames.ora like this:

TEST =   (DESCRIPTION =     (ADDRESS_LIST =         (ADDRESS =                  (PROTOCOL = TCP)           (Host = testdboracle)           (Port = 1521)         )     )     (CONNECT_DATA = (SID = ORCL)     )   )

Installation test

To verify that the installation was correct, we will open a sqlplus session against one of our databases

Connect to Your database with:

$ sqlplus scott/tiger@TEST

You can also use the Easy Connect connection string format (does not use TNSNAMES):

$ sqlplus scott/tiger@testdboracle:1521/ORCL

Monitor ssh on non-default port with Nagios

In ssh pluging config /usr/local/nagios/etc/objects/commands.cfg, there an alias named check_ssh_port.
if it not existe you may define it like above:

define command{ command_name check_ssh_port command_line $USER1$/check_ssh  -p $ARG1$ $HOSTADDRESS$ }

in the service file /usr/local/nagios/etc/servers/hosttomonitor.cfg, define you ssh service to monitor like this:

define host{ use                                 linux-server host_name                           hosttomonitor.localnet alias                               hosttomonitor address                             10.10.10.19 max_check_attempts                  5 check_period                        24x7 notification_interval               30 notification_period                 24x7 } define service {         use                         generic-service         host_name                   hosttomonitor.localnet         service_description         SSH2         check_command               check_ssh_port!1422         notifications_enabled       0         }

replace 1422 by you default ssh port and server by your target.

finally restart nagios service

How to solve the problem "caching_sha2_password" problem

How to solve the problem "caching_sha2_password" problem ?

if you log in to MySQL and find an error like below

[root@localhost ~]# mysql -h 127.0.0.1 -P 3306 -u root -p Enter password: ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded: /usr/lib64/mysql/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory

So I found the reason for that error message (at least for my case). It's because MySQL as of version 8.04 and onwards uses caching_sha2_password as default authentication plugin where previously mysql_native_password has been used.

This obviously causes compatibility issues with older services that expect mysql_native_password authentication.

Solutions:

1. Check for an updated version of the client service you are using (most recent workbench for instance).


2. Downgrade the MySQL Server to a version below that change.


3. Change the authentication plugin on a per user basis (I didn't find a global option, maybe there exists one though).

Now regarding option 3 this is as simple as altering the user:

mysql> ALTER USER root IDENTIFIED WITH mysql_native_password BY 'password';

or when creating the user:

mysql> CREATE USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';

How to FIX ORA-00257: archiver error. Connect internal only, until freed.

How to FIX ORA-00257: archiver error. Connect internal only, until freed.


Cause: The archiver process received an error while trying to archive a redo log. If the problem is not resolved soon, the database will stop executing transactions. The most likely cause of this message is the destination device is out of space to store the redo log file.

ORA-00257 is a common error in Oracle. You will usually see ORA-00257 upon connecting to the database because you have encountered a maximum in the flash recovery area (FRA), or db_recovery_file_dest_size .

First, make sure your automatic archiving is enabled. To check the archive lo made, try:

SQL> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 2671 Next log sequence to archive 2676 Current log sequence 2676

Now, note that you can find archive destinations if you are using a destination of USE_DB_RECOVERY_FILE_DEST by:

SQL> show parameter db_recovery_file_dest; NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ db_recovery_file_dest                string      /oracle/fast_recovery_area db_recovery_file_dest_size           big integer 32G

The next step in resolving ORA-00257 is to find out what value is being used for db_recovery_file_dest_size, use:

SQL> SELECT * FROM V$RECOVERY_FILE_DEST; NAME                                     SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES ---------------------------------------- ----------- ---------- ----------------- ---------------    /oracle/fast_recovery_area                3.8174E+10 3.8174E+10                 0             327

You may find that the SPACE_USED is the same as SPACE_LIMIT,

The first step to fixing this issue would be to log into your server and see if you have run out of physical space on one of your disks or mounts. If you have run out of physical space you have a few options.

You can backup your archivelogs and delete input, or

# rman target / RMAN> BACKUP ARCHIVELOG ALL DELETE ALL INPUT;

you can just delete the archivelogs if you won’t need them to restore your database.

# rman target /     RMAN> DELETE NOPROMPT ARCHIVELOG ALL;

you can Increase db_recovery_file_dest_size

SQL> alter system set db_recovery_file_dest_size=64g scope=both;

After all you can restart database

SQL> shutdown immediate; SQL> startup

Setting up NSQ as a Service on CentOS 7 (SystemD)

In this tutorial I will give an example of making nsqlookup, nsqd and nsqadmin run as service in centos 7 (systemD)

first create a configuration file for each of these services and all configurations are placed in the /etc/nsq directory


for the nsqlookupd configuration file it is nsqlookupd.conf and make it like the file below

# cd /etc/nsq # vi nsqlookupd.conf

## log verbosity level: debug, info, warn, error, or fatal log-level = "info" ## <addr>:<port> to listen on for TCP clients tcp_address = "0.0.0.0:4160" ## <addr>:<port> to listen on for HTTP clients http_address = "0.0.0.0:4161" ## address that will be registered with lookupd (defaults to the OS hostname) broadcast_address = "main" ## duration of time a producer will remain in the active list since its last ping inactive_producer_timeout = "300s" ## duration of time a producer will remain tombstoned if registration remains tombstone_lifetime = "45s"

for the nsqd configuration file it is nsqd.conf and make it like the file below

# vi nsqd.conf

## log verbosity level: debug, info, warn, error, or fatal #log-level = "info" ## unique identifier (int) for this worker (will default to a hash of hostname) # id = 5150 ## <addr>:<port> to listen on for TCP clients tcp_address = "0.0.0.0:4150" ## <addr>:<port> to listen on for HTTP clients http_address = "0.0.0.0:4151" ## <addr>:<port> to listen on for HTTPS clients # https_address = "0.0.0.0:4152" ## address that will be registered with lookupd (defaults to the OS hostname) broadcast_address = "127.0.0.1" ## cluster of nsqlookupd TCP addresses nsqlookupd_tcp_addresses = [     "127.0.0.1:4160" ] ## duration to wait before HTTP client connection timeout http_client_connect_timeout = "2s" ## duration to wait before HTTP client request timeout http_client_request_timeout = "5s" ## path to store disk-backed messages data_path = "/var/lib/nsq" ## number of messages to keep in memory (per topic/channel) mem_queue_size = 10000 ## number of bytes per diskqueue file before rolling max_bytes_per_file = 104857600 ## number of messages per diskqueue fsync sync_every = 2500 ## duration of time per diskqueue fsync (time.Duration) sync_timeout = "2s" ## duration to wait before auto-requeing a message msg_timeout = "60s" ## maximum duration before a message will timeout max_msg_timeout = "15m" ## maximum size of a single message in bytes max_msg_size = 1024768 ## maximum requeuing timeout for a message max_req_timeout = "1h" ## maximum size of a single command body max_body_size = 5123840 ## maximum client configurable duration of time between client heartbeats max_heartbeat_interval = "60s" ## maximum RDY count for a client max_rdy_count = 2500 ## maximum client configurable size (in bytes) for a client output buffer max_output_buffer_size = 65536 ## maximum client configurable duration of time between flushing to a client (time.Duration) max_output_buffer_timeout = "1s" ## UDP <addr>:<port> of a statsd daemon for pushing stats # statsd_address = "127.0.0.1:8125" ## prefix used for keys sent to statsd (%s for host replacement) statsd_prefix = "nsq.%s" ## duration between pushing to statsd (time.Duration) statsd_interval = "60s" ## toggle sending memory and GC stats to statsd statsd_mem_stats = true ## the size in bytes of statsd UDP packets # statsd_udp_packet_size = 508 ## message processing time percentiles to keep track of (float) e2e_processing_latency_percentiles = [     1.0,     0.99,     0.95 ] ## calculate end to end latency quantiles for this duration of time (time.Duration) e2e_processing_latency_window_time = "10m" ## path to certificate file tls_cert = "" ## path to private key file tls_key = "" ## set policy on client certificate (require - client must provide certificate, ##  require-verify - client must provide verifiable signed certificate) # tls_client_auth_policy = "require-verify" ## set custom root Certificate Authority # tls_root_ca_file = "" ## require client TLS upgrades tls_required = false ## minimum TLS version ("ssl3.0", "tls1.0," "tls1.1", "tls1.2") tls_min_version = "" ## enable deflate feature negotiation (client compression) deflate = true ## max deflate compression level a client can negotiate (> values == > nsqd CPU usage) max_deflate_level = 6 ## enable snappy feature negotiation (client compression) snappy = true

for the nsqadmin configuration file it is nsqadmin.conf and make it like the file below

# vi  nsqadmin.conf

## log verbosity level: debug, info, warn, error, or fatal log-level = "info" ## <addr>:<port> to listen on for HTTP clients http_address = "0.0.0.0:4171" ## graphite HTTP address graphite_url = "" ## proxy HTTP requests to graphite proxy_graphite = false ## prefix used for keys sent to statsd (%s for host replacement, must match nsqd) statsd_prefix = "nsq.%s" ## format of statsd counter stats statsd_counter_format = "stats.counters.%s.count" ## format of statsd gauge stats statsd_gauge_format = "stats.gauges.%s" ## time interval nsqd is configured to push to statsd (must match nsqd) statsd_interval = "60s" ## HTTP endpoint (fully qualified) to which POST notifications of admin actions will be sent notification_http_endpoint = "" ## nsqlookupd HTTP addresses nsqlookupd_http_addresses = [     "127.0.0.1:4161" ] ## nsqd HTTP addresses (optional) #nsqd_http_addresses = [ #    "127.0.0.1:4151" #]

let's make a service for all nsq service

• nsqlookupd



# cd /etc/systemd/system # vim nsqlookupd.service




[Unit] Description=nsqlookup daemon Service After=network.target [Service] PrivateTmp=yes ExecStart=/usr/local/nsq/bin/nsqlookupd -config /etc/nsq/nsqlookupd.conf Restart=always [Install] WantedBy=multi-user.target



• nsqd



# vim nsqd.service




[Unit] Description=Realtime distributed messaging (nsqd) After=network.target [Service] PrivateTmp=yes ExecStart=/usr/local/nsq/bin/nsqd -config /etc/nsq/nsqd.conf Restart=always [Install] WantedBy=multi-user.target



• nsqadmin



v# vim nsqadmin.service




[Unit] Description=nsqadmin daemon Service (nsqadmin) After=network.target [Service] PrivateTmp=yes ExecStart=/usr/local/nsq/bin/nsqadmin -config /etc/nsq/nsqadmin.conf Restart=always [Install] WantedBy=multi-user.target

enable all nsq service

# systemctl enable nsqlookupd.service Created symlink from /etc/systemd/system/multi-user.target.wants/nsqlookupd.service to /etc/systemd/system/nsqlookupd.service.

# systemctl enable nsqd.service Created symlink from /etc/systemd/system/multi-user.target.wants/nsqd.service to /etc/systemd/system/nsqd.service.

# systemctl enable nsqadmin.service Created symlink from /etc/systemd/system/multi-user.target.wants/nsqadmin.service to /etc/systemd/system/nsqadmin.service.

here we go start the service

# systemctl start nsqlookupd # systemctl start nsqd # systemctl start nsqadmin

to check service run or not

# systemctl status nsqlookupd ● nsqlookupd.service - nsqlookup daemon Service    Loaded: loaded (/etc/systemd/system/nsqlookupd.service; enabled; vendor preset: disabled)    Active: active (running) since Tue 2019-04-09 03:38:40 EDT; 1h 41min ago  Main PID: 5193 (nsqlookupd)    CGroup: /system.slice/nsqlookupd.service            └─5193 /usr/local/nsq/bin/nsqlookupd -config /etc/nsq/nsqlookupd.c... Apr 09 05:18:06 main.coba.net nsqlookupd[5193]: [nsqlookupd] 2019/04/09 05:1...) Hint: Some lines were ellipsized, use -l to show in full.

# systemctl status nsqd ● nsqd.service - Realtime distributed messaging (nsqd)    Loaded: loaded (/etc/systemd/system/nsqd.service; enabled; vendor preset: disabled)    Active: active (running) since Tue 2019-04-09 04:58:21 EDT; 22min ago  Main PID: 5234 (nsqd)    CGroup: /system.slice/nsqd.service            └─5234 /usr/local/nsq/bin/nsqd -config /etc/nsq/nsqd.conf Apr 09 04:58:21 main.coba.net nsqd[5234]: [nsqd] 2019/04/09 04:58:21.319327 ...0 Hint: Some lines were ellipsized, use -l to show in full.

# systemctl status nsqadmin ● nsqadmin.service - nsqadmin daemon Service (nsqadmin)    Loaded: loaded (/etc/systemd/system/nsqadmin.service; enabled; vendor preset: disabled)    Active: active (running) since Tue 2019-04-09 04:59:13 EDT; 21h ago  Main PID: 5249 (nsqadmin)    CGroup: /system.slice/nsqadmin.service            └─5249 /usr/local/nsq/bin/nsqadmin -config /etc/nsq/nsqadmin.conf Apr 09 04:59:13 main.coba.net systemd[1]: Started nsqadmin daemon Service (n.... Apr 09 04:59:13 main.coba.net nsqadmin[5249]: [nsqadmin] 2019/04/09 04:59:13...) Hint: Some lines were ellipsized, use -l to show in full

That all's