=head1 NAME

pg_activity - Realtime PostgreSQL database server monitoring tool

=head1 SYNOPSIS

B<pg_activity> [option..] [connection string]

=head1 DESCRIPTION

Command line tool for PostgreSQL server activity monitoring.

pg_activity must run on the same server as the instance and
as the user running the instance (or root) to show
CPU, MEM, READ or WRITE columns and other system information.

=head2 THE HEADER

The first line of the header displays PostgreSQL's version, the host name, the
connection string, the refresh rate and the duration mode.

The header is then divided in tree groups: B<instance>, B<worker processes>,
B<system>.  The information is filtered according to the filter parameters when
appropriate. This is shown in the following descriptions with the "(filtered)"
mention. Depending on the version you are on, some information might not be
available. In that case, it will be replaced by a dash.

The B<instance> group displays information aubout the PostgreSQL instance (or
cluster). This group can be displayed or hidden with the I Key.

Global :

=over 2

=item - B<uptime>: since when is the instance running;

=item - B<dbs size>: total size of the databases (filtered);

=item - B<growth>: growth in B/s of the databases (filtered);

=item - B<cache hit ratio>: the percentage of page read from the PostgreSQL's cache since last snapshot (filtered).

=back

Sessions :

=over 2

=item - B<total>: session count (filtered) / max_connections;

=item - B<active>: number of active sessions (filtered);

=item - B<idle>: number of idle sessions (filtered);

=item - B<idle in txn>: number of sessions who are in the idle in transaction state (filtered);

=item - B<idle in txn abrt>: number of sessions who are in the idle in transaction aborted state (filtered);

=item - B<waiting>: number of sessions that are waiting for a lock (filtered).

=back

Activity :

=over 2

=item - B<tps>: transaction per second (sum of commit & rollback for all databases / time elapsed since last snapshot) (filtered);

=item - B<insert/s>: number of inserts per second (filtered);

=item - B<updates/s>: number of updates per second (filtered);

=item - B<delete/s>: number of deletes per second (filtered);

=item - B<tuples returned/s>: number of tuples returned per second (filtered);

=item - B<temp files>: number of temporary files created on the instance;

=item - B<temp size>: total temporary file size on the instance.

=back

The B<worker processes> group displays information about backgroup workers,
autovacuum processes, wal senders and wal receivers. It also gives information
about replication slots. Except for the autovacuum workers count, most of this
information is not related to a specific database, therefore their values will
be zero when the data is filtered.

Worker processes:

=over 2

=item - B<total>: total worker count / maximum number of worker slots, parallel workers and logical replication workers are taken from this amount (filtered);

=item - B<logical workers>: logical replication worker count / maximum number of logical replication workers (filtered);

=item - B<parallel workers>: parallel worker count for maintenance & queries / maximum number of parallel workers (filtered).

=back

Other processes & information:

=over 2

=item - B<autovacuum workers>: number of autovacuum worker in action / maximum number of autovacuum workers (filtered);

=item - B<wal senders>: number of wal senders / maximum number of wal senders processes (filtered);

=item - B<wal receivers>: number of wal receivers / maximum number of wal receiver processes (filtered);

=item - B<repl. slots>: number of replication slots / maximum number of replication slots (filtered).

=back

The last group displays B<system information>:

=over 2

=item - B<Mem.>: total / free / used and buff+cached memory with the related percentages;

=item - B<Swap>: total / free / used swap;

=item - B<IO>: the number of IO per second, current Read and Write throughput (aggregated data gathered with the psutil library);

=item - B<Load>: CPU load for the last 1, 5, 15 minutes;

=back

=head2 THE RUNNING QUERIES PANEL

The running queries panel shows all running queries, transactions or backends
(depending on the B<DURATION_MODE> setting) which have lasted for more than
B<min duration> seconds. It displays the following information:

=over 2

=item - B<PID>: process id of the backend which executes the query;

=item - B<XMIN>: xmin horizon of the backend;

=item - B<DATABASE>: database specified in the connection string;

=item - B<APP>: application name specified in the connection string;

=item - B<USER>: user name specified in the connection string;

=item - B<CLIENT>: client address or "local" in case of linux socker connection;

=item - B<CPU%>: percentage of CPU used by the backend as reported by the psutil library;

=item - B<MEM%>: percentage of memory used by the backend as reported by the psutil library;

=item - B<READ/s>:  read thruput as reported by the psutil library;

=item - B<WRITE/s>: write thruput as reported by the psutil library;

=item - B<TIME>: time since the beginning of the query / transaction / backend start depending on the B<DURATION_MODE> currently in use;

=item - B<Waiting>: for PostgreSQL 9.6+: a specific wait event or nothing. Otherwise, a boolean indicating if we are waiting for a Lock;

=item - B<IOW>: boolean indicating that the process is waiting for IO as reported by the psutil library;

=item - B<state>: state of the backend;

=item - B<Query>: the query.

=back

=head2 THE WAITING QUERIES PANEL

The waiting queries view displays queries that are waiting for a lock. It
shows the following information:

=over 2

=item - B<PID>: process id of the backend which executes the query;

=item - B<DATABASE>: database specified in the connection string;

=item - B<APP>: application name specified in the connection string;

=item - B<USER>: user name specified in the connection string;

=item - B<CLIENT>: client address or "local" in case of linux socker connection;

=item - B<RELATION>: the name of the relation being locked if applicable;

=item - B<TYPE>: the type of lock;

=item - B<MODE>: the mode of the lock;

=item - B<TIME+>: the duration of the query, transaction or session depending on the B<DURATION_MODE> setting;

=item - B<state>: the state of the transaction;

=item - B<Query>: the query.

=back

=head2 THE BLOCKING QUERIES PANEL

The blocking queries view displays the queries that lock an object which is
required by another session. It shows following information:

=over 2

=item - B<PID>: process id of the backend which executes the query;

=item - B<DATABASE>: database specified in the connection string;

=item - B<APP>: application name specified in the connection string;

=item - B<USER>: user name specified in the connection string;

=item - B<CLIENT>: client address or "local" in case of linux socker connection;

=item - B<RELATION>: the name of the relation being locked if applicable;

=item - B<TYPE>: the type of lock;

=item - B<MODE>: the mode of the lock;

=item - B<TIME+>: the duration of the query, transaction or session depending on the B<DURATION_MODE> setting;

=item - B<Waiting>: for PostgreSQL 9.6+: a specific wait event or nothing. Otherwise, a boolean indicating if we are waiting for a Lock;

=item - B<state>: the state of the transaction;

=item - B<Query>: the query.

=back

=head1 COMMAND-LINE OPTIONS

=head2 CONFIGURATION

=over 2

=item B<-P PROFILE>, B<--profile=PROFILE>

	Configuration profile matching a PROFILE.conf file in ${XDG_CONFIG_HOME:~/.config}/pg_activity/ or /etc/pg_activity/, or a built-in profile.

=back

=head2 OPTIONS

=over 2

=item B<--blocksize=BLOCKSIZE>

	Filesystem blocksize (default: 4096).

=item B<--rds>

	Enable support for AWS RDS (implies --no-tempfiles and filters out the rdsadmin database from space calculation).

=item B<--output=FILEPATH>

	Store running queries as CSV.

=item B<--db-size>, B<--no-db-size>

	Enable/disable total size of DB.

=item B<--tempfiles>, B<--no-tempfiles>

	Enable/disable tempfile count and size.

=item B<--walreceiver>, B<--no-walreceiver>

	Enable/disable walreceiver checks.

=item B<-w, --wrap-query>

	Wrap query column instead of truncating.

=item B<--min-duration=SECONDS>

	Don't display queries with smaller than specified duration (in seconds).

=item B<--filter=FIELD:REGEX>

	Filter activities with a (case insensitive) regular expression applied on selected fields. Known fields are: dbname.

	Note: It's possible to filter out a database with negative lookahead, eg: '^(?!database_name)'

=item B<--help>

	Show this help message and exit.

=item B<--version>

	Show program's version number and exit.

=back

=head2 CONNECTION OPTIONS

=over 2

=item B<-U USERNAME>, B<--username=USERNAME>

	Database user name.

=item B<-p PORT>, B<--port=PORT>

	Database server port.

=item B<-h HOSTNAME>, B<--host=HOSTNAME>

	Database server host or socket directory.

=item B<-d DBNAME>, B<--dbname=DBNAME>

    Database name to connect to.

=back

=head2 PROCESS DISPLAY OPTIONS

=over 2

=item B<--pid>, B<--no-pid>

	Enable/disable PID.

=item B<--xmin>, B<--no-xmin>

	Enable/disable XMIN.

=item B<--database>, B<--no-database>

	Enable/disable DATABASE.

=item B<--user>, B<--no-user>

	Enable/disable USER.

=item B<--client>, B<--no-client>

	Enable/disable CLIENT.

=item B<--cpu>, B<--no-cpu>

	Enable/disable CPU%.

=item B<--mem>, B<--no-mem>

	Enable/disable MEM%.

=item B<--read>, B<--no-read>

	Enable/disable READ/s.

=item B<--write>, B<--no-write>

	Enable/disable WRITE/s.

=item B<--time>, B<--no-time>

	Enable/disable TIME+.

=item B<--wait>, B<--no-wait>

	Enable/disable W.

=item B<--app-name>, B<--no-app-name>

	Enable/disable APP.

=back

=head2 HEADER DISPLAY OPTIONS

=over 2

=item B<--no-inst-info>

	Hide instance information.

=item B<--no-sys-info>

	Hide system information.

=item B<--no-proc-info>

	Hide workers process information.

=back

=head2 OTHER DISPLAY OPTIONS

=over 2

=item B<--refresh>

	Change the refresh rate, allowed values are: 0.5, 1, 2, 3, 4, 5 (in seconds) (default: 2).

=back

=head1 ENVIRONMENT VARIABLES

=over 2

All the environment variables supported by libpq (PostgreSQL's query
protocol) are supported by pg_activity.

See: https://www.postgresql.org/docs/current/libpq-envars.html

=back

=head1 INTERACTIVE COMMANDS

=over 2

=item B<r>     Sort by READ/s, descending.

=item B<w>     Sort by WRITE/s, descending.

=item B<c>     Sort by CPU%, descending.

=item B<m>     Sort by MEM%, descending.

=item B<t>     Sort by TIME+, descending.

=item B<y>     Copy focused query to clipboard.

=item B<T>     Change duration mode: query, transaction, backend.

=item B<Space> Pause on/off.

=item B<v>     Change queries display mode: full, truncated, indented.

=item B<UP / DOWN> Scroll process list.

=item B<k / j> Scroll process list.

=item B<q>     Quit.

=item B<+>     Increase refresh time. Maximum value: 3s.

=item B<->     Decrease refresh time. Minimum Value: 1s.

=item B<F1/1>  Running queries monitoring.

=item B<F2/2>  Waiting queries monitoring.

=item B<F3/3>  Blocking queries monitoring.

=item B<h>     Help page.

=item B<R>     Refresh.

=item B<D>     Refresh database size.

=back

=head1 NAVIGATION MODE

=over 2

=item B<UP / k>    Move up the cursor.

=item B<DOWN / j>  Move down the cursor.

=item B<PAGE UP>    Move the cursor to the first line.

=item B<PAGE DOWN>  Move the cursor to the last line.

=item B<K>     Terminate the current backend/tagged backends.

=item B<C>     Cancel the current backend/tagged backends.

=item B<Space> Tag or untag the process.

=item B<q>     Quit.

=item B<Other> Back to activity.

=back

=head1 MISSING DATA IN THE UI?

pg_activity is best used with a user owning the SUPERUSER privilege. Ordinary
users can only see all the information about their own sessions (sessions
belonging to a role that they are a member of). In rows about other sessions,
many columns will be null or not picked by pg_activity. It will impact both the
information gathered in the B<HEADER> section and the B<ACTIVITY PANEL>

If a user doesn't have the CONNECT privilege on a database the
pg_database_size() function will fail and pg_activity will crash. The
B<--no-db-size> option can be used in this case. This situation is frequent for
cloud database where the service provider has created a service database with a
restricted access.

Some settings are visible only to superusers or members of pg_read_all_settings
such as the data_directory guc. If the user cannot read this parameter or
access the pid file in the PGDATA directory, the B<system information HEADER>
group will not be displayed. The B<%CPU>, B<%MEM>, B<Read/s> and B<Write/s>
columns will also be missing from the B<ACTIVITY PANEL>.

On some OS like MacOS, psutil's io_counters() is not implemented. The effects
are the same as those described when data_directory is not readable.

pg_activity needs to access the pgsql_tmp directory stored in all tablespaces
in order to compute the number and size of the temporary files. This requires
the usage of the pg_ls_tmpdir() function (or pg_ls_dir() and pg_stats_file()
for versions older than PostgreSQL 12). The user needs to own the SUPERUSER
privilege, be a member of pg_read_server_files or have EXECUTE rights on the
function to fetch the information. When the number of tempfiles grows a lot,
the query might also timeout. The first failure to access this data will
disable tempfile statistics. The feature can be disabled with
B<--no-tempfiles>.

Aurora doesn't provide the pg_stat_get_wal_receiver() function.  Therefore
there is no wal receiver data in the B<process & information HEADER> group. The
first failure to access this data might be logged by the PostgreSQL, the
following checks will be skipped.  Wal receiver checks can be completely
disabled with B<--no-walreceiver>.

Finally, some information is not available in older version of PostgreSQL,
the fields will therefore be empty.

=head1 EXAMPLES

PGPASSWORD='mypassword' pg_activity -U pgadmin -h 127.0.0.1 --no-client

pg_activity -h /var/run/postgresql

pg_activity -h myserver -p 5433 -d nagios -U nagios

=cut