Provided by: pgcluu_3.1-1_all bug

NAME

       pgCluu - PostgreSQL Cluster utilization

DESCRIPTION

       pgCluu is a PostgreSQL performance monitoring and auditing tool.

       It is a Perl program used to perform a full audit of a PostgreSQL Cluster and System
       performance. It is divided in two parts:

       - A collector used to grab statistics on the PostgreSQL cluster using the psql command
       line utility and sar from the sysstat package.

       - A pure Perl grapher that will generate all HTML and charts output without any
       requirements.

       If you don't need system utilization reports or don't want to install the sysstat package,
       you can disable it at command line. You will only have reports about your PostgreSQL
       Cluster. If you are running pgCluu from a central server using option -h to monitor
       remotely a PostgreSQL Cluster, the call to sar is automatically disabled.

       If you just want to have system utilization reports or generate graphs from a sar data
       file, it's also possible.

SYNOPSIS

       PostgreSQL and System metrics collector.

               pgcluu_collectd [options] output_dir

       Report generator.

               pgcluu [options] -o report_dir input_dir

REQUIREMENT

       pgCluu comes with two Perl scripts. You need a modern Perl distribution, the psql client
       and the sar command line utility (sysstat). The sysstat package is optional, you can still
       use pgCluu to generate reports about your PostgreSQL Cluster without it.

       Charts are rendered using a Javascript library so you don't need anything else.  Your
       browser will do all the work.

INSTALLATION

   Installation from package
       Installation of pgCluu can be done through the PostgreSQL Global Development Group (PGDG)
       repositories. See how to install the PGDG repositories at the following URLs for Debian
       and Ubuntu:

               https://wiki.postgresql.org/wiki/Apt

       and Redhat, CentOs, Fedora, Scientific Linux and Oracle Enterprise Linux:

               https://yum.postgresql.org/

       Once it is done you can simply install pgCluu with commands:

               sudo apt install pgcluu
               sudo yum install pgcluu

       Look at the package information to know where files are specifically installed. See next
       two chapters to see which default installation paths are used.

   Installation from sources
       Download the tarball from SourceForge and unpack the archive:

               tar xzf pgcluu-3.x.tar.gz
               cd pgcluu-3.x/
               perl Makefile.PL
               make && sudo make install

       This will copy the Perl scripts pgcluu_collectd and pgcluu into /usr/local/bin directory
       and the man page to /usr/local/share/man/man1/pgcluu.1p.gz.  Those are the default
       installation directories for 'site' install on some well-known distribution but the path
       could change.

       If you want to install all under /usr location, use INSTALLDIRS='vendor' as an argument of
       Makefile.PL. The script will be installed into /usr/bin/pgcluu and the manpage into
       /usr/share/man/man1/pgcluu.1p.gz.

       For example, to install everything just like Debian does, proceed as follows:

               perl Makefile.PL INSTALLDIRS=vendor

       By default INSTALLDIRS is set to site.

       The directory where statistics will be saved is /var/lib/pgcluu/data and the default
       directory for reports is /var/lib/pgcluu/report.

       The CGI script is installed into /var/lib/cgi-bin/pgcluu.cgi and the Apache configuration
       file into /etc/apache/conf-available/pgcluu.conf. This file allow acces to resources files
       (CSS and JS files) from installation directory /usr/local/share/pgcluu/rsc/. Access is
       granted to local user only by default.

       All scripts (pgcluu_collectd, pgcluu and pgcluu.cgi) are reading configuration file from
       /usr/local/etc/pgcluu.conf. This file is mainly use by the CGI script but some directives
       are dedicated to pgcluu_collectd and pgcluu script to define the retention days for
       example.

   Custom installation
       The installation of pgCluu can be fully customized through environment variables
       (RSCDIR,CGIDIR,CONFDIR,PIDDIR,STATDIR,APACHECONF,MANDIR, DOCDIR,SYSTEMDDIR,RETENTION).
       These variables are passed to Makefile.PL as command line arguments or can be exported as
       environment variables before running "perl Makefile.PL".

       The default values for these variables are:

           DESTDIR     => /usr/local
           INSTALLDIRS => site
           CONFDIR     => DESTDIR/etc
           PIDDIR      => /var/run/postgres
           STATDIR     => /var/lib/pgcluu/data
           REPORTDIR   => /var/lib/pgcluu/data
           RSCDIR      => DESTDIR/share/pgcluu
           CGIDIR      => /usr/lib/cgi-bin
           APACHECONF  => /etc/apache2/conf-available
           MANDIR      => DESTDIR/share/man
           DOCDIR      => DESTDIR/share/doc
           SYSTEMDIR   => DESTDIR/lib/systemd/system
           RETENTION   => 0

       If INSTALLDIRS is set to 'vendor':

           CONFDIR     => /etc
           DESTDIR     => /usr

       The configuration file is auto-generated by the Makefile.PL script and saved into
       CONFDIR/pgcluu.conf. If the destination file exists it is not overridden. The file is also
       saved as example in the directory DOCDIR/pgcluu/examples/pgcluu.conf.dist

       The directory where pgcluu_colletd will store statistics is defined with STATDIR which is
       by default /var/lib/pgcluu/data. The directory where pgcluu will generate static html
       reports is defined by REPORTDIR.  The default is /var/lib/pgcluu/report. Both directory
       must be owned by the postgres user.

       The man page is saved as DESTDIR/share/man/pgcluu.1p.gz and a symbolic link
       pgcluu_collectd.1p.gz is created to this file. The documentation, README, changelog.gz,
       LICENSE files are saved under DESTDIR/share/doc/.

       For the CGI mode, the resources (css and js files from the cgi-bin/rsc) are saved under
       the DESTDIR/share/pgcluu/rsc directory. The CGI script is saved under
       /usr/lib/cgi-bin/pgcluu.cgi. The Apache configuration file under
       /etc/apache2/conf-available/pgcluu.conf with a symbolic link
       /etc/apache2/conf-enabled/pgcluu.conf created to this file. Its content:

           Alias /pgcluu RSCDIR/
           <Directory RSCDIR/>
               Options FollowSymLinks MultiViews
               AllowOverride None
               Require local
               #Require ip 192.1.168.0/24
           </Directory>

       The systemd files (pgcluu_collectd.service,pgcluu.service,pgcluu.timer) are saved as
       examples into DOCDIR/pgcluu/examples/ and into the systemd directory SYSTEMDDIR/

       The right path to the configuration file is set into all scripts pgcluu, pgcluu_collectd
       and pgcluu.cgi. The path where the pid file must be saved is replaced into pgcluu_collectd
       with the value of PIDFILE variable.

       Paths to scripts, pid directory, statistics and reports are replaced in all systemd
       service files following the values of the environment variable explain here.

USAGE

       Manually

       See next two chapters for a complete description of the command line options.  For the
       impatient, here some simple commands that could be run as postgres user:

               mkdir /tmp/stat_db1/
               pgcluu_collectd -D -i 60 /tmp/stat_db1/
               LOG: Detach from terminal with pid: 11323

       or with more options

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ -h 10.10.1.1 -U postgres -d mydb
               LOG: Detach from terminal with pid: 14671

       wait some time and activity on your PostgreSQL Cluster...  Then stop the pgcluu_collectd
       daemon and generate the report:

               pgcluu_collectd -k
               LOG: Received terminating signal.
               mkdir /tmp/report_db1/
               pgcluu -o /tmp/report_db1/ /tmp/stat_db1/

       You should obtain something like example at http://pgcluu.darold.net/example/

       By default all javascript, css and the webfont fontawesome are automatically generated
       into the output directory if those files does not already exits.

       Using systemd unit files

       pgcluu comes with systemd service files:

           - pgcluu_collectd.service: execute pgcluu_collectd as a daemon to collect statistics.
           - pgcluu.service: execute pgcluu to generate reports.
           - pgcluu.timer: run periodically pgcluu.service

       These files are installed automatically by the install script or the package into
       /lib/systemd/system/. To activate these services proceed as follow:

               systemctl daemon-reload
               systemctl enable pgcluu_collectd.service
               systemctl enable pgcluu.service
               systemctl enable pgcluu.timer
               systemctl start pgcluu_collectd.service
               systemctl start pgcluu.timer

       Be warn that storing indefinitely statistics with pgcluu_collectd can fill you disk space
       in the short or medium term. You have to remove obsolete statistics manually using a cron
       job or using the embedded retention feature by adding option '--retention ndays' to
       pgcluu_collectd call or by changing the value of STATS_COLLECTD_RETENTION configuration
       directive in file /usr/local/etc/pgcluu.conf or /etc/pgcluu.conf file following your
       installation.  You can also set STATS_REPORT_RETENTION to limit the retention of reports
       directories or use option '--retention ndays' with pgcluu.

       If you want to use the CGI mode you also have activate pgcluu caching by enabling value
       STATS_REPORT_CACHING in the configuration file and using pgcluu.service+pgcluu.timer. If
       you don"t want to use systemd you can simply run pgcluu script with the -C option and
       execute it periodically through a cron job.

       Note that the systemd service files set the privilege to the data and report directory to
       user postgres and group www-data. By this way reports are readable through an httpd server
       for static reports and data are readable through the CGI if enabled. Command executed by
       the pgcluu_collectd.service file (daemon part) are:

               /bin/mkdir -p $STATDIR
               /bin/chown postgres:www-data $STATDIR
               /bin/chmod u=rwX,g=rsX,o= $STATDIR

       The pgcluu.service file (client part) execute commands:

               /bin/mkdir -p $REPORTDIR
               /bin/chown postgres:www-data $REPORTDIR
               /bin/chmod u=rwX,g=rsX,o= $REPORTDIR

       In case you don't want to use systemd service files you will have to execute these
       commands manually before tunning pgCluu.

COLLECTING STATISTICS

       To generate reports about your PostgreSQL Cluster Utilization you must collect statistics
       before. pgcluu_collectd is here for that. It can be run in a daemon mode (option -D) or in
       interactive mode for debugging purpose. All you need is to provide a directory where data
       will be stored. Statistics will be pooled at a default interval of 60 seconds, using
       option -i you can customize it. See below for a complete list of command line options.

   pgcluu_collectd usage
       usage: pgcluu_collectd [options] output_dir

               output_dir: full path to directory where pgcluu_collectd will
                           store statistics.

       options:

         -B, --enable-buffercache enable buffercache statistics if pg_buffercache
                                  extension is installed.
         -c, --capture            create a snapshot of the PostgreSQL installation
                                  into tmp/pgcluu_capture.tar.gz.
         -C, --end-counter=NUM    terminate program after NUM reports.
         -d, --dbname=DATABASE    database name to connect to. Default to current user.
         -D, --daemonize          detach from console and enter in daemon mode.
         -E, --end-after=SECOND   self terminate program after a given number of seconds.
                                  Can be written: 7200 or 120M or 2H, for days use 7D for
                                  example to stop collecting data after seven days.
         -f, --pid-file=FILE      path to pid file. Default: /var/run/postgresql/pgcluu_collectd.pid.
         -h, --host=HOSTNAME      database server host or socket directory
         -i, --interval=NUM       time to wait between runs
         -k, --kill               stop current pgcluu_collectd running daemon.
         -m, --metric=METRIC      set a coma separated list of metrics to perform.
         -M, --max-size=SIZE      self terminate program when the size of the output dir
                                  exceed a given size. Can be written: 2GB or 2000MB.
         -p, --port=PORT          database port(s) to connect to. Defaults to 5432.
         -P, --psql=BIN           path to the psql command. Default: psql.
         -Q, --no-statement       do not collect queries statistics from pg_stat_statements.
         -r, --rotate-daily       force daily rotation of data files.
         -R, --rotate-hourly      force hourly rotation of data files.
         -s, --sar=BIN            path to sar sysstat command. Default: sar.
         -S, --disable-sar        disable collect of system statistics with sar.
         -T, --no-tablespace      disable lookup at tablespace when the connect user
                                  is not superuser to avoid printing an error message.
         -U, --dbuser=USERNAME    database user to connect as. Default to current user.
         -v, --verbose            Print out debug informations.
         -V, --version            Show pgcluu_collectd version and exit.
         -W, --password=pass      database password.
         -z, --compress           force compression of rotated data files.
         --included-db=DATABASE   collect statistics only for those databases present
                                  in a comma separated list of database names.
         --list-metric            list available metrics actions that can be performed.
         --sysinfo                get operating system information and exit (sysinfo.txt).
         --no-sysinfo             do not collect operating system information at all.
         --no-database            do not collect database statistics at all.
         --pgbouncer-args=OPTIONS Option to used to connect to the pgbouncer system
                                  database. Ex: -p 6432 -U postgres -h 192.168.1.100
                                  You must at least give one parameter to enable
                                  pgbouncer monitoring.
         --sar-file=FILE          path to sar output data file for sysstat stats
                                  Default to output_dir/sar_stats.dat.
         --stat-type all|user     Set stats tables to read. Values: 'all' or 'user' to
                                  look at pg_stat_(all|user) tables. Default: user.
         --pgversion X.Y          force the PostgreSQL version to the given value.
         --pgservice NAME         Name of service inside of the pg_service.conf file.
         --exclude-time RANGE     exclude a laps of time by giving the start and end
                                  hours.
         --cron-user=USERNAME     collect crontab settings for the given username (in
                                  this case pgcluu_collectd need to be run as root).
                                  Default is to use USERNAME environment variable or
                                  postgres when it is not defined.
         --package-list=CMD       command to list PostgreSQL packages. Default is to
                                  autodetect package type and using command 'rpm -qa'
                                  or 'dpkg -l'. If you have an other system you can
                                  set a custom command. A filter on keyword 'postgres'
                                  is appended to the command: ' | grep postgres'.
         --retention NDAYS        number of rolling days to keep in data directory in
                                  incremental mode. Default is to store indefinitely.
         --help                   print usage

       Use those options to execute sar on the remote host defined by the -h option, otherwise it
       will be executed locally:

         --enable-ssh             activate the use of ssh to run sysstat remotely.
         --ssh-program ssh        path to the ssh program to use. Default: ssh.
         --ssh-user username      connection login name. Default to running user.
         --ssh-identity file      path to the identity file to use.
         --ssh-timeout second     timeout to ssh connection failure. Default 10 seconds.
         --ssh-options  options   list of -o options to use for the ssh connection. Options
                                  always used:
                                        -o ConnectTimeout=$ssh_timeout
                                        -o PreferredAuthentications=hostbased,publickey

       For example, as postgres user to monitor locally a full PostgreSQL cluster:

               mkdir /tmp/stat_db1/
               pgcluu_collectd -D -i 60 /tmp/stat_db1/

       to collect statistics from pgbouncer too, and limit database statistics to a single
       database:

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ -h 10.10.1.1 -U postgres -d mydb
                       --pgbouncer-args='-p 5342'

       to disable statistics collect between 22:30 and 06:30 the next day:

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ --exclude-time "22:30-06:30"

       to collect statistics from a remote server:

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ -h 10.0.0.1 -U postgres --disable-sar

       the same but with collecting system statistics using remote sar calls:

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ -h 10.0.0.1 -U postgres --enable-ssh
                       --ssh-user postgres --ssh-identity /var/lib/postgresql/.ssh/id_rsa.pub

       You may need a .pgpass and be able to establish passwordless ssh connections to be able to
       collect statistics from remote hosts.

       Then after some time and activities on the database, stop the daemon as follow:

               pgcluu_collectd -k

       or by sending sigterm to the pgcluu_collectd's pid.

       You can run the collector in incremental mode using a daily or a hourly statistics
       rotation:

               pgcluu_collectd -D -i 60 /tmp/stat_db1/ --rotate-daily

       On a server with huge activity you may want to use --rotate-hourly and compression mode
       with --compress option. If you have limited disk space you can restrict the retention time
       of statistics files using option --retention with the storage day limit.

   Statistics files
       The output directory with all statistics collected should look likes:

               /tmp/stat_db1/
               |-- commit_memory.csv
               |-- end-pg_statio_user_indexes.csv
               |-- end-pg_statio_user_sequences.csv
               |-- end-pg_statio_user_tables.csv
               |-- end-pg_stat_user_functions.csv
               |-- end-pg_stat_user_indexes.csv
               |-- end-pg_stat_user_tables.csv
               |-- end-pg_stat_xact_user_functions.csv
               |-- end-pg_stat_xact_user_tables.csv
               |-- fs_stat_use.csv
               |-- pg_class_size.csv
               |-- pg_database_size.csv
               |-- pg_db_role_setting.csv
               |-- pg_hba.conf
               |-- pg_ident.conf
               |-- pg_nondefault_settings.csv
               |-- pg_prepared_xact.csv
               |-- pg_settings.csv
               |-- pg_stat_archiver.csv
               |-- pg_stat_bgwriter.csv
               |-- pg_stat_connections.csv
               |-- pg_stat_count_indexes.csv
               |-- pg_stat_database_conflicts.csv
               |-- pg_stat_database.csv
               |-- pg_stat_hash_indexes.csv
               |-- pg_stat_invalid_indexes.csv
               |-- pg_statio_user_indexes.csv
               |-- pg_statio_user_sequences.csv
               |-- pg_statio_user_tables.csv
               |-- pg_stat_locks.csv
               |-- pg_stat_missing_fkindexes.csv
               |-- pg_stat_redundant_indexes.csv
               |-- pg_stat_replication.csv
               |-- pg_stat_unlogged.csv
               |-- pg_stat_unused_indexes.csv
               |-- pg_stat_user_functions.csv
               |-- pg_stat_user_indexes.csv
               |-- pg_stat_user_tables.csv
               |-- pg_stat_xact_user_functions.csv
               |-- pg_stat_xact_user_tables.csv
               |-- pg_tablespace_size.csv
               |-- pg_xlog_stat.csv
               |-- postgresql.auto.conf
               |-- postgresql.conf
               |-- sar_stats.dat
               |-- sysinfo.txt

       Then now you can proceed with pgcluu to generate reports.

   Rotation and compression
       When used the --rotate-daily or --rotate-hourly commands line option will force
       pgcluu_collectd to rotate daily or hourly all statistic's files. In this case, statistics
       files will be created in a subdirectory based on rotation frequency,
       output_dir/year/month/day[/hour]. This is called the incremental mode.

       To save filesystem space it is possible to enable compression of all rotated files during
       the rotation process. Just activate the -z or --compress command line option. You can also
       use the --retention option to set the storage time limit in days.

   Incremental mode
       This mode is enabled when --rotate-daily or --rotate-hourly command line options are used.
       It allow pgcluu to build reports incrementally by days or hours. In this mode you don't
       have to build reports per day or hour pgcluu will do the work automatically, just give it
       the top statistics directory.

               pgcluu -o /var/www/pgcluu/reports/ /var/lib/pgcluu/data/

       pgcluu will detect that --rotate-daily or --rotate-hourly have been used to collect data
       and generate reports for each day or hours stored. Previous directories already processed
       will not be processed again unless this was the the last one.

       The daily or hourly basis statistic storage also allow the use of the CGI script
       pgcluu.cgi to have dynamic reports and temporal search. See "Using dynamic mode" chapter.

       When used the --rotate-daily or --rotate-hourly commands line option will force
       pgcluu_collectd to rotate daily or hourly all statistic's files. In this case, statistics
       files will be created in a subdirectory based on rotation frequency,
       output_dir/year/month/day[/hour]. This is called the incremental mode.

       To save filesystem space it is possible to enable compression of all rotated files during
       the rotation process. Just activate the -z or --compress command line option. You can also
       use the --retention option to set the storage time limit in days.

   Capture mode
       The goal of this mode is to be able to obtain a simple report about the PostgreSQL
       installation without collected metrics others than database and tablespace size. This
       report can be use by ITs to better understand the configuration and things that need to be
       tuned.

       To enable this mode, just run pgcluu_collectd with the single option -c or --capture.
       Other command line options will not be taken in account.  pgcluu_collectd will create e
       temporary directory /tmp/pgcluu_capture to store temporary data and will removed if after
       building a compressed tar archive: /tmp/pgcluu_capture.tar.gz. This is this archive that
       can be used with pgcluu to build a snapshot report of the instance. pgcluu will
       automatically detect this mode.

GENERATING REPORTS

   Static HTML reports
       To generate a pgCluu report about a PostgreSQL Cluster you must, at least, have a
       directory that contains all data files generated by pgcluu_collectd or pgstats. In this
       directory, if you have a file named sar_stats.dat or sadc_stats.dat for binary sadc data
       file, it will be taken to build report about system utilization. If you just want to make
       a report from a sar file use the -i or -I options.

       usage: pgcluu [options] [-i sar_file | -I sadc_file] [input_dir]

               input_dir: directory where pgcluu_collectd or pgstats and sar data
                          files are stored.

       options:
         -b, --begin  datetime      start date/time for the data to be parsed.
         -C, --cache                generate cache files only (.bin), no html output.
         -d, --db-only dbname       only report for the whole cluster and the given
                                    database name. You can use it multiple time or
                                    give a comma separated list of database name.
         -D, --device-only dev      only report I/O stats for a particular device
                                    You can use it multiple time or give a comma
                                    separated list of device name, ex: sda,sdc.
         -e, --end    datetime      end date/time for the data to be parsed.
         -i, --sar-file=FILE        path to the sar text data file to read to generate
                                    system reports. Default to input_dir/sar_stats.dat.
         -I, --sadc-file=FILE       sadc binary data file to read to generate system
                                    reports. Default to input_dir/sadc_stats.dat.
         -n, --top-number           Top number of tables or indexes I/O stats to show.
                                    Default is set to top 10. Set it to 0 to show all.
         -N, --network-only iface   only report stats for a particular network interface.
                                    You can use it multiple times or give a comma separated
                                    list of network interfaces, ex: eth0,eth1.
         -o, --output=DIR           output directory
         -r, --reverse-date         By default pgcluu look at mm/dd/yy format in sar file.
                                    When enabled pgcluu will look at dd/mm/yy format.
         -s, --sadf=BIN             path to the sadf sysstat command used to read the
                                    sadc binary data file. Default: /usr/bin/sadf.
         -S, --disable-sar          disable collect of system statistics with sar.
         -t, --with-table table     Only report for the whole tables and the given
                                    table name. You can use it multiple time or
                                    give a comma separated list of database name.
         -T, --no-table             Do not report statistics related to tables.
         -v, --verbose              Print out debug informations.
         -V, --version              Show pgcluu version and exit.
         -x, --external-menu        Save menu in menu.html and load it into each report
                                    using w3-include-html attribut from w3.js. This will
                           only work if acces to HTML reports is through a Web
       server, not using the file:// protocol.
         -z, --timezone +/-XX       Set the number of hour(s) from GMT of the timezone.
                                    Use this to adjust date/time from the sar output,
                                    pgcluu use GMT time to draw charts.
         -Z, --stats-timezone +/-XX Set the number of hour(s) from GMT of the timezone.
                                    Use this to adjust date/time from the cluster and
                                    system stats output, pgcluu use GMT time.
         --from-sa-file             instruct pgcluu that file specified by the -i option
                                    uses the standard system activity daily data file.
         --charset                  used to set the HTML charset to be used.
                                    Default: utf-8.
         --retention NDAYS          number of rolling days to keep in report directory.
                                    Default is to store indefinitely.
         --help                     print usage

       For example, you can generate all HTML reports from data files stored into /tmp/stat_db1/
       with the following commands:

               mkdir /tmp/report_db1/
               pgcluu -o /tmp/report_db1/ /tmp/stat_db1/

       If you just want reports of some databases, use the following:

               pgcluu -o /tmp/report_db1/ /tmp/stat_db1/ --db-only "db1,db2,db3"

       If you just want to create a report from a sar output file:

               sar -p -A 10 60 > /root/my_sar_file.txt
               pgcluu -o /tmp/report_sar/ -i /root/my_sar_file.txt

       or from a daily sa file:

               sar -p -A -f /var/log/sa/sa18 > /root/my_sar_file.txt
               pgcluu -o /tmp/report_sar/ -i /root/my_sar_file.txt --from-sa-file

       and from a sa binary file:

               pgcluu -o /tmp/report_sar/ -i /var/log/sysstat/sa22

       or the sa text file if you don't have the same version of sysstat:

               pgcluu -o /tmp/report_sar/ -i /var/log/sysstat/sar23 --from-sa-file

       If pgcluu_collectd have been run in incremental mode you can limit the number of retention
       days used for the reports:

               pgcluu -o /tmp/report_sar/ /tmp/stat_db1/ --retention 30

       A static report will be built for each day or hour following the rotation used with
       pgcluu_collectd.

   Dynamic reports (CGI)
       Dynamics reports are build by a CGI script named pgcluu.cgi that can be found in the cgi-
       bin repository of the source code. It allow you to select the time period to build reports
       and to look at all differents reports for this period just as with static HTML reports.
       After installation from sources or binary packages the CGI might be found in
       /usr/lib/cgi-bin/pgcluu.cgi or /var/www/cgi-bin/pgcluu.cgi following your distribution.

       To use pgCluu in CGI mode, you need a Web server (here we use Apache) and a cron task to
       build the cache periodically.

       First enable CGI mode.

               sudo a2enmod cgi
               sudo service apache2 restart

       Then the CGI need to find the statistics directory where pgcluu_collectd mostly
       /var/lib/pgcluu/data/. The content of this repository must be readable by the Apache user
       (www-data).

       Take care to restrict access to your server and the CGI as information about your database
       and server are exposed in the reports.

       The CGI script, pgcluu.cgi, use resources files (CSS and javascript). They are stored in
       the cgi-bin/rsc/ directory of the source distribution. Install this repository onto the
       DocumentRoot of your Web server, for example:

               sudo mkdir /var/www/pgcluu/
               sudo cp -rf cgi-bin/rsc /var/www/pgcluu/

       Then edit /etc/pgcluu.conf, copy it from sources cgi-bin/pgcluu.conf if it doesn't exists.
       Change the RSC_BASE and INPUT_DIR configuration directive to match your installation. Here
       in our example:

               RSC_BASE        /pgcluu/rsc/
               INPUT_DIR       /var/lib/pgcluu/data

       Now we can start the data collection. For the moment pgcluu.conf is only read by the CGI
       pgcluu.cgi but this might change in the future.

       To let pgCluu start collecting data, you can use the following command (you can change it
       to however you like). We will need postgres user for this.

               sudo su - postgres
               /usr/local/bin/pgcluu_collectd -D -i 60 --rotate-daily /var/lib/pgcluu/data

       This will rotate you data daily. This is also the default in the systemd service file.

       Plugging the CGI directly to the CSV statistics files will result in very slow generation
       reports. To improve speed caching must be used, you must execute periodically pgcluu in
       cache mode. Run it manually the first time

               /usr/local/bin/pgcluu --cache /var/lib/pgcluu/data

       then add a cron task to execute the command each five or ten minutes:

               */5 * * * * /usr/local/bin/pgcluu --cache /var/lib/pgcluu/data

       If you are using systemd pgcluu.timer service then caching can be enabled using
       STATS_REPORT_CACHING directive. Enabling this mode generate cache files (*.bin) in the
       statistics directory and disable static HTML reports generation.

       To see your reports, go to the following URL:

               http://localhost/cgi-bin/pgcluu.cgi

       Or change localhost by your fqdn server name.

       Note that here pgcluu_collectd and pgcluu scripts are found in /usr/local/bin/ which is
       the default for an installation from sources but with an installation from binary package
       you might find them into /usr/bin/.

       The CGI mode allow you to select the period of time used to generate the statistics
       reports. Using default pgcluu_collectd 60 seconds interval, a daily graph will have 1440
       points. Having too much timeseries to render is not a good point for performances so we
       are limiting to the first seven days of the selected period. This mean a maximum of 10080
       points for one week, this seems a safe limit. Feel free to increase or reduce the limit
       following the server and client resources. This is controlled by

               MAX_RENDERED_DAYS       7

       configuration directive in pgcluu.conf

LICENSE

       Copyright (c) 2012-2019, Gilles Darold

       pgCluu is licenced under the PostgreSQL Licence a liberal Open Source license, similar to
       the BSD or MIT licenses. That mean that all parts of the program are open source and free
       of charge.

               Permission to use, copy, modify, and distribute this software and its
               documentation for any purpose, without fee, and without a written agreement
               is hereby granted, provided that the above copyright notice and this
               paragraph and the following two paragraphs appear in all copies.

               IN NO EVENT SHALL Dalibo BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
               SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
               ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
               Dalibo HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

               Gilles Darold SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
               LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
               PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS,
               AND Gilles Darold HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
               UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

       This is the case for both, pgcluu_collectd and the grapher pgcluu programs.

AUTHORS

       pgCluu is an original development of Gilles Darold.

       Some parts of the collector are taken from pgstats a C program writen by Guillaume Lelarge
       and especially the SQL queries including the compatibility with all PostgreSQL versions.
       See https://github.com/gleu/pgstats

       Btw pgCluu grapher is compatible with files generated by pgstats, sar and sadc so you can
       use it independantly to graph those data. Some part of the sar output parser are taken
       from SysUsage. See http://sysusage.darold.net/