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Sumo Logic

Metrics for the Sumo Logic PostgreSQL App

This reference lists all of the metrics collected for the Sumo Logic PostgreSQL App, along with an explanation for each metric gauge.

Metrics

Metric Name

Brief

Type

pg_blks.heap_hit

Number of buffer hits

gauge

pg_blks.heap_read

Number of disk blocks read

gauge

pg_blks.idx_hit

Number of index buffer hits

gauge

pg_blks.idx_read

Number of index blocks read

gauge

hpg_blks.tidx_hit

Number of TOAST index buffer hits

gauge

pg_blks.tidx_read

Number of TOAST index blocks read

gauge

pg_blks.toast_hit

Number of TOAST buffer hits

gauge

pg_blks.toast_read

Number of disk blocks read

gauge

pg_db_size

Size of the database on disk, in bytes

gauge

pg_n_tup_c.del

Number of delete operations

gauge

pg_n_tup_c.hot_upd

Number of update operations not requiring index update

gauge

pg_n_tup_c.ins

Number of insert operations

gauge

pg_n_tup_c.upd

Number of update operations

gauge

pg_n_tup_g.dead

Number of dead rows in the database

gauge

pg_n_tup_g.live

Number of live rows in the database

gauge

pg_numbackends

Number of server processes

gauge

pg_scan.idx

Number of index scans

gauge

pg_scan.idx_tup_fetch

Number of rows read from index scans

gauge

pg_scan.seq

Number of sequential scans

gauge

pg_scan.seq_tup_read

Number of rows read from sequential scans

gauge

pg_xact.commit

Number of commits

gauge

pg_xact.num_deadlocks

Number of deadlocks detected by the database

gauge

pg_xact.rollback

Number of rollbacks

gauge

pg_db_table_size

Size of the table on disk, in bytes

gauge

pg_replication_lag

time elapsed in seconds since pg_last_xact_replay_timestamp().

gauge

pg_index_scan_stat

Number of accesses to specific index

gauge

Metric gauges

This section provides an explanation for each of the PostgreSQL metrics gauges listed in the previous table.

Metric Gauge

Description

pg_blks.heap_hit

This metric shows how many read operations were served from the buffer in memory, so that a disk read was not necessary. This only includes hits in the PostgreSQL buffer cache, not the operating system’s file system cache.

pg_blks.heap_read

This metric shows how many disk blocks have been read.

pg_blks.idx_hit

This metric shows many index access operations have been served from the buffer in memory.

pg_blks.idx_read

This metric shows how many disk blocks have been read by index access operations.

pg_blks.tidx_hit 

This metric shows how many read operations were served from the buffer in memory, so that a disk read was not necessary. This only includes hits in the PostgreSQL buffer cache, not the operating system’s file system cache.

pg_blks.tidx_read

This metric shows how many disk blocks have been read by index access operations on TOAST tables.

pg_blks.toast_hit

This metric shows how many TOAST table reads have been served from buffer in memory.

pg_blks.toast_read

This metric shows how many disk blocks have been read on TOAST tables.

pg_db_size

This metric shows the size of the database on disk, in bytes.

pg_n_tup_c.del

This metric shows how many delete operations have been performed.

pg_n_tup_c.hot_upd

This metric shows how many update operations have been performed without requiring an index update

pg_n_tup_c.ins

This metric shows how many insert operations are performed.

pg_n_tup_c.upd

This metric shows how many update operations are performed.

pg_n_tup_g.dead

This metric shows how many dead rows in the database. Rows that are deleted or obsoleted by an update are not physically removed from their table; they remain present as dead rows until a VACUUM is done.

pg_n_tup_g.live

This metric shows the number of live rows in the database.

pg_numbackends

This metric shows how many server processes this database is using.

pg_scan.idx

This metric shows how many index scans have been performed across all the tables.

pg_scan.idx_tup_fetch

This metric shows how many rows have been read by index scans across all tables.

pg_scan.seq

This metric shows how many sequential scans have been performed across all the tables. This is generally referred to as table scan. It is usually the least optimized approach for randomly accessing data in the database tables.

pg_scan.seq_tup_read

This metric shows how many rows are read from sequential scans across all the tables. Sequential scans, sometimes referred to as table scans, are the least optimized approach of accessing the data.

pg_xact.commit

This metric shows how many commits have been processed by the database. This usually represents the number of transactions performed by the database.

pg_xact.num_deadlocks

This metric shows how many deadlocks have been detected by the database. Deadlocks are caused by two or more competing actions that are unable to finish because each is waiting for the other’s lock or resources.

pg_xact.rollback

This metric shows how many rollbacks have happened in the database. This could be caused by transactional failure, errors in statements or data validations.

pg_db_table_size

This metric shows the size of table(s) on disk, in bytes.

pg_replication_lag

This metric shows time elapsed in seconds since the last transaction replayed during recovery. This is the time at which the commit or abort WAL record for that transaction was generated on the primary.

pg_index_scan_stat

This metric shows the number of accesses to specific index by table and database.