Consultor Eletrônico

Status: Unverified

GOAL:

What does the wait column mean reported by promon?

GOAL:

Wait column values reported by promon

FIX:

If a process is reported by promon as waiting, there are various types of resources that the process is waiting on. The following is adapted from the documentation.

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Waits reported by promon > 1. User Control > 1. Display all entries

REC - Record lock. The process is waiting for a locked record to be freed. The numeric column shows the record ID number of the record the process is waiting for.

SCHM - Schema lock. The process is waiting for the schema lock. There is one schema lock; only one user at a time can update any part of the schema.

TSK - Another task (transaction to end). The process is waiting to access (or skip) a record that has been marked for deletion, or whose key field value has been changed, by a task (transaction) that has not yet terminated. When the task terminates, this process can resume executing.

DEAD - Process termination. The process has actually terminated, although it still appears in the process list. This can happen if a process is killed with the UNIX kill-9 command.

BUFF - Database buffer. The process is waiting for a database buffer.

DB - Database service. The process is waiting for the database server.

IX - Index lock. The process is waiting for an index lock.

MT - Microtransaction. The process is waiting for a microtransaction.

READ - Block read
The process is waiting to read a block.

WRT - Block write. The process is waiting to write a block.


Note that -

REC, SCHM and TSK are application waits. There is no time limit on how long one of these locks can be held.

BUFF, DB, IX, MT READ and WRT are for short-duration (micro- to milliseconds) locks used internally by Progress.


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Waits reported by promon > R&D > 1. Status Displays > 4. Processes/Clients > 1. All Processes

If no value is displayed, the process is not waiting on any database-related events.


Lock Waits

REC Row (record) lock.
SCH Schema lock.
TRAN Transaction commit.


Resource Waits

AIRD After-image buffer read from disk.
AIWR After-image buffer write to disk.
BIRD Before-image buffer read from disk.
BIWR Before-image buffer write to disk.
BKEX Exclusive lock on database buffer.
BKSH Share lock on database buffer.
BKSI Share lock with intent to update on database buffer.
DBBK Database buffer being backed up.
DBRD Database buffer read from disk.
DBWR Database buffer write to disk.
RGET Row get lock.
TXE Transaction commit lock.


Latch Waits

AIB After-image buffer latch.
BFP Buffer pool latch.
BHT Buffer pool hash table latch.
BUF Buffer pool buffer latch.
CPQ Checkpoint queue latch.
DLC Index delete chain.
GST Global storage pool latch.
IXD Index delete chain latch.
LKF Lock table free chain latch.
LKP Lock table purge chain latch.
LKT Lock table latch.
LRS Secondary LRU chain (not currently implemented).
LRU Buffer pool LRU chain latch.
MTX Log space allocation latch.
PWQ Page writer queue latch.
SCH Shared schema cache latch.
SEQ Sequence cache latch.
TXQ Transaction queue latch.
TXT Transaction table latch.
USR User table latch.