public String log_archive(int flags)
The DbEnv.log_archive method
returns an array of log or database filenames.
By default, DbEnv.log_archive returns the names of all of the log
files that are no longer in use (for example, that are no longer
involved in active transactions), and that may safely be archived for
catastrophic recovery and then removed from the system. If there are
no filenames to return,
DbEnv.log_archive returns null.
The flags value must be set to 0 or by bitwise inclusively OR'ing together one or
more of the following values:
- All pathnames are returned as absolute pathnames, instead of relative
to the database home directory.
- Return the database files that need to be archived in order to recover
the database from catastrophic failure. If any of the database files
have not been accessed during the lifetime of the current log files,
DbEnv.log_archive will not include them in this list. It is also
possible that some of the files referred to by the log have since been
deleted from the system.
- Return all the log filenames, regardless of whether or not they are in
The Db.DB_ARCH_DATA and Db.DB_ARCH_LOG flags are mutually
Log cursor handles (returned by the DbEnv.log_cursor method) may have open
file descriptors for log files in the database environment. Also, the
Berkeley DB interfaces to the database environment logging subsystem (for
example, DbEnv.log_put and DbTxn.abort) may allocate log cursors
and have open file descriptors for log files as well. On operating
systems where filesystem related system calls (for example, rename and
unlink on Windows/NT) can fail if a process has an open file descriptor
for the affected file, attempting to move or remove the log files listed
by DbEnv.log_archive may fail. All Berkeley DB internal use of log cursors
operates on active log files only and furthermore, is short-lived in
nature. So, an application seeing such a failure should be restructured
to close any open log cursors it may have, and otherwise to retry the
operation until it succeeds. (Although the latter is not likely to be
necessary; it is hard to imagine a reason to move or rename a log file
in which transactions are being logged or aborted.)
See the db_archive manual page for more information on database
The DbEnv.log_archive method throws an exception that encapsulates a non-zero error value on
The DbEnv.log_archive method may fail and throw an exception encapsulating a non-zero error for the following conditions:
- An invalid flag value or parameter was specified.
The log was corrupted.
The DbEnv.log_archive method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv.log_archive method may fail and
throw a DbRunRecoveryException,
in which case all subsequent Berkeley DB calls will fail in the same way.
DbEnv, DbLogc, DbLsn
Logging Subsystem and Related Methods
Copyright Sleepycat Software