Logstat Command Output – Current Log File Header
The Current Log File Header gives quantitative information on the logging system, such as the size of the log file, log buffers, and CP interval.
Consistency Points (CP)—In the Current log file header section is a group of numbers preceded by the label CP. These numbers, like the numbers following Begin and End, are in three groups. The middle group refers to the block marking the last consistency point. This consistency point contains a list of all open transactions and open databases at that time.
In the sample output shown here, the block marking the consistency point is 13909. CPs shorten the recovery window after a system goes down. Instead of reading from BOF to EOF, the last CP is read and recovery begins from there.
----Current log file header----------------------------------------------------
Block size: 4096 Block count: 2048 Partitions: 1 Buffer count: 4
CP interval: 102 Logfull interval: 1945 Abort interval: 1536
Last Transaction Id: 00002D5B2D5BFA03 Last LSN: <1187966476, 1054245>
Begin: <1187966477:13909:2968> CP: <1187966477:13909:2968> End: <1187966477,13909,1012>
Forced LGA,LSN: <1187966477,13909,1012>,<1187966476,1054245>
Percentage of log file in use or reserved: 6
Log file blocks reserved by recovery system: 180
Archive Window: <0,0,0>..<0,0,0>
Previous CP: <0,0,0>
Status: ONLINE,ARCHIVE,CPFLUSH
Active Log(s): II_LOG_FILE
The Current Log File Header section has the following fields:
Block size
Indicates the size of the log buffer and log file blocks in bytes. The log file is organized as a series of blocks that are laid down in a circular fashion and used for on line backup.
Block count
Indicates the size of the log file in blocks
Partitions
Indicates the number of log partitions in the log file
Buffer count
Indicates the number of log file buffers. All processes connected to the logging system share the buffers.
CP interval
Indicates the number of blocks between consistency points. CPs may also be caused by other events, such as archiver PURGEs and online checkpoints.
Logfull interval
Indicates the number of log file blocks used before LOG_FULL is signaled
Abort interval
Indicates the number of log file blocks that must be used before a FORCE_ABORT is signaled
Last Transaction Id
Indicates the ID of the last transaction to write a log record
Last LSN
Indicates the log sequence number associated with the last written log record
Begin, CP, End
Indicates the log addresses of the beginning of the log file, the last consistency point, and the end of the log file
Forced LGA,LSN
Indicates the LGA (physical log file address) and LSN of the last log record written to the log file
Percentage of log file in use or reserved
Indicates the percentage of the log file that has either been used or is reserved for use by the recovery system
Log file blocks reserved by recovery system
Indicates the number of log file blocks reserved for transaction recovery operations. Space reserved by a transaction is freed when the transaction commits normally, or it is used to write compensation log records during transaction abort processing.
Archive Window
Indicates the segment of the log file that can be examined by the archiver for journal or dump processing
Previous CP
Indicates the log file address of the last consistency point. This is the position in the log file where the last consistency point was taken.
Status
Indicates the current logging system status. Status can be one or more of the following values:
ACP_SHUTDOWN—the archiver is preparing to shut down. (This indicates that an rcpconfig command with the shutdown option has been issued.)
ARCHIVE—the archiver process is archiving journaled transactions to the journal files.
BCPSTALL—the logging system is requesting the recovery process to start writing a begin consistency point.
CKP_SBACKUP—the logging system marks the start of online backup. It marks this block as the online backup start block (SB). Ckpdb starts backing up the database.
CLOSEDB—the logging system is in the process of closing a database.
CPFLUSH—DBMS Servers are flushing their modified pages to disk, that is, a consistency point is being taken.
CPNEEDED—the logging system is about to take a consistency point.
CPWAKEUP—the logging system is synchronizing the fast-commit threads.
DISABLE_DUAL_LOGGING—the logging system is in the process of disabling dual logging.
DUAL_LOGGING—dual logging is enabled. (Note that this does not mean that both primary and dual logs are active. For active logs look at the Active Log(s) field.)
ECP—the logging system is requesting that the recovery process start writing an end consistency point.
ECPDONE—the logging system has taken an end consistency point. This status flag is present most of the time while the logging system is functioning normally.
FORCE_ABORT—the force-abort-limit has been reached; the oldest open transaction will be aborted.
IMM_SHUTDOWN—the logging system has been told to shut down immediately. (This is displayed when the user invokes rcpconfig with the imm_shutdown option.) Note that the logging system does not perform any housekeeping as part of the shutdown process. The recovery process then becomes responsible for backing out any uncommitted transactions left in the log file once the logging system has been restarted.
JSWITCHDONE—the logging system has completed a switch of the journal file. This status flag is present most of the time while the logging system is functioning normally.
LOGFULL—the log file is full. The system administrator should determine the cause of this and increase the log file size. A warning indicator is also displayed.
MAN_ABORT—the logging system has been requested to manually abort a distributed transaction.
MAN_COMMIT—the logging system has been requested to manually commit a distributed transaction.
ONLINE—the logging system is on line. The logging and recovery systems are operating OK.
OPENDB—the logging system is in the process of opening a database.
PURGEDB—a database has been closed by the last user who had it open; the archiver is archiving transactions that belong to this database.
RCP_RECOVER—the recovery process is recovering transactions from a runaway DBMS.
RECOVER—the logging system has requested the recovery process to perform recovery.
START_ARCHIVER—this important status indicates that the archiver has stopped and must be restarted by the DBA. This is not done automatically. If the DBA does not do it, the log file will eventually fill up, reaching the LOG_FILE_FULL limit, and cause the system to stall.
START_SHUTDOWN—the logging system is shutting down. As part of the shutdown process, the logging system commits to disk all the committed transactions and backs out any uncommitted ones. The archiver also journals all the committed transactions for tables with journaling enabled.
Active Log(s)
Displays log files that are active.