Man page - pg_activity(1)

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Package:  pg-activity
apt-get install pg-activity

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• pg_activity(1)
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• pg-activity

Manual

PG_ACTIVITY

NAME
SYNOPSIS
DESCRIPTION
THE HEADER
THE RUNNING QUERIES PANEL
THE WAITING QUERIES PANEL
THE BLOCKING QUERIES PANEL
COMMAND-LINE OPTIONS
CONFIGURATION
OPTIONS
CONNECTION OPTIONS
PROCESS DISPLAY OPTIONS
HEADER DISPLAY OPTIONS
OTHER DISPLAY OPTIONS
ENVIRONMENT VARIABLES
INTERACTIVE COMMANDS
NAVIGATION MODE
MISSING DATA IN THE UI?
EXAMPLES

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NAME

pg_activity - Realtime PostgreSQL database server monitoring tool

SYNOPSIS

pg_activity [option..] [connection string]

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.

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: instance , worker processes , 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 instance group displays information aubout the PostgreSQL instance (or cluster). This group can be displayed or hidden with the I Key.

Global :
- uptime : since when is the instance running;
- dbs size : total size of the databases (filtered);
- growth : growth in B/s of the databases (filtered);
- cache hit ratio : the percentage of page read from the PostgreSQL's
cache since last snapshot (filtered).

Sessions :
- total : session count (filtered) / max_connections;
- active : number of active sessions (filtered);
- idle : number of idle sessions (filtered);
- idle in txn : number of sessions who are in the idle in transaction
state (filtered);
- idle in txn abrt : number of sessions who are in the idle in
transaction aborted state (filtered);
- waiting : number of sessions that are waiting for a lock (filtered).

Activity :
- tps : transaction per second (sum of commit & rollback for all
databases / time elapsed since last snapshot) (filtered);
- insert/s : number of inserts per second (filtered);
- updates/s : number of updates per second (filtered);
- delete/s : number of deletes per second (filtered);
- tuples returned/s : number of tuples returned per second (filtered);
- temp files : number of temporary files created on the instance;
- temp size : total temporary file size on the instance.

The 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:
- total : total worker count / maximum number of worker slots, parallel
workers and logical replication workers are taken from this amount
(filtered);
- logical workers : logical replication worker count / maximum number of
logical replication workers (filtered);
- parallel workers : parallel worker count for maintenance & queries /
maximum number of parallel workers (filtered).

Other processes & information:
- autovacuum workers : number of autovacuum worker in action / maximum
number of autovacuum workers (filtered);
- wal senders : number of wal senders / maximum number of wal senders
processes (filtered);
- wal receivers : number of wal receivers / maximum number of wal
receiver processes (filtered);
- repl. slots : number of replication slots / maximum number of
replication slots (filtered).

The last group displays system information :
- Mem. : total / free / used and buff+cached memory with the related
percentages;
- Swap : total / free / used swap;
- IO : the number of IO per second, current Read and Write throughput
(aggregated data gathered with the psutil library);
- Load : CPU load for the last 1, 5, 15 minutes;

THE RUNNING QUERIES PANEL

The running queries panel shows all running queries, transactions or backends (depending on the DURATION_MODE setting) which have lasted for more than min duration seconds. It displays the following information:
- PID : process id of the backend which executes the query;
- XMIN : xmin horizon of the backend;
- DATABASE : database specified in the connection string;
- APP : application name specified in the connection string;
- USER : user name specified in the connection string;
- CLIENT : client address or "local" in case of linux socker connection;
- CPU% : percentage of CPU used by the backend as reported by the psutil
library;
- MEM% : percentage of memory used by the backend as reported by the
psutil library;
- READ/s : read thruput as reported by the psutil library;
- WRITE/s : write thruput as reported by the psutil library;
- TIME : time since the beginning of the query / transaction / backend
start depending on the DURATION_MODE currently in use;
- Waiting : for PostgreSQL 9.6+: a specific wait event or nothing.
Otherwise, a boolean indicating if we are waiting for a Lock;
- IOW : boolean indicating that the process is waiting for IO as
reported by the psutil library;
- state : state of the backend;
- Query : the query.

THE WAITING QUERIES PANEL

The waiting queries view displays queries that are waiting for a lock. It shows the following information:
- PID : process id of the backend which executes the query;
- DATABASE : database specified in the connection string;
- APP : application name specified in the connection string;
- USER : user name specified in the connection string;
- CLIENT : client address or "local" in case of linux socker connection;
- RELATION : the name of the relation being locked if applicable;
- TYPE : the type of lock;
- MODE : the mode of the lock;
- TIME+ : the duration of the query, transaction or session depending on
the DURATION_MODE setting;
- state : the state of the transaction;
- Query : the query.

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:
- PID : process id of the backend which executes the query;
- DATABASE : database specified in the connection string;
- APP : application name specified in the connection string;
- USER : user name specified in the connection string;
- CLIENT : client address or "local" in case of linux socker connection;
- RELATION : the name of the relation being locked if applicable;
- TYPE : the type of lock;
- MODE : the mode of the lock;
- TIME+ : the duration of the query, transaction or session depending on
the DURATION_MODE setting;
- Waiting : for PostgreSQL 9.6+: a specific wait event or nothing.
Otherwise, a boolean indicating if we are waiting for a Lock;
- state : the state of the transaction;
- Query : the query.

COMMAND-LINE OPTIONS

CONFIGURATION

-P PROFILE , --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.

OPTIONS

--blocksize=BLOCKSIZE

Filesystem blocksize (default: 4096).

--rds

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

--output=FILEPATH

Store running queries as CSV.

--db-size , --no-db-size

Enable/disable total size of DB.

--tempfiles , --no-tempfiles

Enable/disable tempfile count and size.

--walreceiver , --no-walreceiver

Enable/disable walreceiver checks.

-w, --wrap-query

Wrap query column instead of truncating.

--min-duration=SECONDS

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

--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: 'ˆ(?!database_name)'

--help

Show this help message and exit.

--version

Show program's version number and exit.

CONNECTION OPTIONS

-U USERNAME , --username=USERNAME

Database user name.

-p PORT , --port=PORT

Database server port.

-h HOSTNAME , --host=HOSTNAME

Database server host or socket directory.

-d DBNAME , --dbname=DBNAME

Database name to connect to.

PROCESS DISPLAY OPTIONS

--pid , --no-pid

Enable/disable PID.

--xmin , --no-xmin

Enable/disable XMIN.

--database , --no-database

Enable/disable DATABASE.

--user , --no-user

Enable/disable USER.

--client , --no-client

Enable/disable CLIENT.

--cpu , --no-cpu

Enable/disable CPU%.

--mem , --no-mem

Enable/disable MEM%.

--read , --no-read

Enable/disable READ/s.

--write , --no-write

Enable/disable WRITE/s.

--time , --no-time

Enable/disable TIME+.

--wait , --no-wait

Enable/disable W.

--app-name , --no-app-name

Enable/disable APP.

HEADER DISPLAY OPTIONS

--no-inst-info

Hide instance information.

--no-sys-info

Hide system information.

--no-proc-info

Hide workers process information.

OTHER DISPLAY OPTIONS

--refresh

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

ENVIRONMENT VARIABLES

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

INTERACTIVE COMMANDS

r Sort by READ/s, descending.
w Sort by WRITE/s, descending.
c Sort by CPU%, descending.
m Sort by MEM%, descending.
t Sort by TIME+, descending.
y Copy focused query to clipboard.
T Change duration mode: query, transaction, backend.
Space Pause on/off.
v Change queries display mode: full, truncated, indented.
UP / DOWN Scroll process list.
k / j Scroll process list.
q Quit.
+ Increase refresh time. Maximum value: 3s.
- Decrease refresh time. Minimum Value: 1s.
F1/1 Running queries monitoring.
F2/2 Waiting queries monitoring.
F3/3 Blocking queries monitoring.
h Help page.
R Refresh.
D Refresh database size.

NAVIGATION MODE

UP / k Move up the cursor.
DOWN / j Move down the cursor.
PAGE UP Move the cursor to the first line.
PAGE DOWN Move the cursor to the last line.
K Terminate the current backend/tagged backends.
C Cancel the current backend/tagged backends.
Space Tag or untag the process.
q Quit.
Other Back to activity.

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 HEADER section and the 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 --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 system information HEADER group will not be displayed. The %CPU , %MEM , Read/s and Write/s columns will also be missing from the 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 --no-tempfiles .

Aurora doesn't provide the pg_stat_get_wal_receiver() function. Therefore there is no wal receiver data in the 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 --no-walreceiver .

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

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

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