[firebird-support] Temporarily stop and disable garbage collection
Hi We have a need to ensure garbage collection is not running in a given database. Ideally we would stop / cancel any garbage collection in progress, do our stuff, then turn garbage collection back on. Is this possible? Thanks Rob
Re: [firebird-support] Temporarily stop and disable garbage collection
> Is this possible? http://www.firebirdsql.org/file/documentation/reference_manuals/user_manuals/html/gfix-cmdline.html Sure. see parameter: -housekeeping set sweep interval usage: gfix [options] plausible options are: -activate activate shadow file for database usage -attach shutdown new database attachments -buffersset page buffers -commit commit transaction -cache shutdown cache manager -full validate record fragments (-v) -force force database shutdown -fetch_password fetch_password from file -housekeeping set sweep interval -ignore ignore checksum errors -kill kill all unavailable shadow files -list show limbo transactions -mend prepare corrupt database for backup -mode read_only or read_write -no_update read-only validation (-v) -online database online -prompt prompt for commit/rollback (-l) -password default password -rollback rollback transaction -sql_dialectset database dialect n -sweep force garbage collection -shut shutdown -two_phase perform automated two-phase recovery -tran shutdown transaction startup -useuse full or reserve space for versions -user default user name -validate validate database structure -write write synchronously or asynchronously -z print software version number http://www.firebirdsql.org/file/documentation/reference_manuals/user_manuals/html/gfix-housekeeping.html Disabling Automatic Sweeping If you set the sweep interval to zero then automatic sweeping will be disabled. This implies that there will be no automatic housekeeping done so your database performance will not suffer as a result of the processing requirements of the automatic sweep. bye... eMeL
Re: [firebird-support] Temporarily stop and disable garbage collection
> > > Is this possible? > > http://www.firebirdsql.org/file/documentation/reference_manuals/user_manuals/html/gfix-cmdline.html > > Sure. > > see parameter: -housekeeping set sweep interval > Hi I was probably not specific enough in my problem description :) I know that I can disable garbage collection via the cmd line. What I am looking for is the ability to... 1. Cancel any existing garbage collection 2. Disable garbage collection 3. Do my stuff 4. Re enable garbage collection. I know I can to 2 and 4 via gFix but item 1 is the issue. Also I would want to use the services manager rather than command line tools. Thanks Rob
Re: [firebird-support] Temporarily stop and disable garbage collection
Em 25/4/2013 21:58, Robert martin escreveu: >>> Is this possible? >> http://www.firebirdsql.org/file/documentation/reference_manuals/user_manuals/html/gfix-cmdline.html >> >> Sure. >> >> see parameter: -housekeeping set sweep interval >> > Hi > > I was probably not specific enough in my problem description :) > > I know that I can disable garbage collection via the cmd line. What I > am looking for is the ability to... > > 1. Cancel any existing garbage collection > 2. Disable garbage collection > 3. Do my stuff > 4. Re enable garbage collection. > > > I know I can to 2 and 4 via gFix but item 1 is the issue. Also I would > want to use the services manager rather than command line tools. > > Thanks > Rob > > > GFIX will disable sweep. Garbage Collection and Sweep is not the same thing. There is a lot of detailed explanations about it, search for Ann messages and you will see the diference. Besides the diference between Garbage Collection and Sweep, there are diferent modes of Garbage Collection in SuperServer x Classic Server. AFAIR there is a parameter that you could use in your transaction (TPB parameter) that will disable garbage collection, this is the trick that gbak does when using the -g swiitch see you !
Re: [firebird-support] Temporarily stop and disable garbage collection
Here's the discussion: > > > > I know that I can disable garbage collection via the cmd line. What I > > am looking for is the ability to... > > > > 1. Cancel any existing garbage collection > > 2. Disable garbage collection > > 3. Do my stuff > > 4. Re enable garbage collection. > That's an odd request. It could reflect one of two things: a desire to maintain db_key stability or a misunderstanding of garbage collection. The first is possible. The second is likely. I'm going to assume the second, but would like to understand what it is you think you're going to accomplish. > > > > > > I know I can to 2 and 4 via gFix but item 1 is the issue. Also I would > > want to use the services manager rather than command line tools. > > You can't do 2 or 4 with gfix or anything else. There is a TPB parameter which gbak uses that tells the current transaction not to participate in garbage collection, but that's probably not what you want. Before I repeat my explanation of the purpose and implementation of garbage collection, why don't you explain what you're trying to do. Good luck, Ann [Non-text portions of this message have been removed]
Re: [firebird-support] Temporarily stop and disable garbage collection
> That's an odd request. It could reflect one of two things: a desire to > maintain > db_key stability or a misunderstanding of garbage collection. The first is > possible. The second is likely. I'm going to assume the second, but would > like to understand what it is you think you're going to accomplish. > Hi Actually neither. We have a process where the system does an backup and then restores back. The process actually renames the source DB file, does the backup and then restores the backup with the initial file name. We know that users are logged off because the application doing the process is the server part of a client/server system. We have recently discovered this process sometimes fails because the file is in use. My suspicion is that it is in use by the sweep process (which I apparently been incorrectly referring to as garbage collection). Although all applications have disconnected from the database, the FDB file cannot be renamed. Stopping the FB service allows a rename. So It is something that FB is doing. I don't really want to re design the above functionality if It can be avoided, so I thought I might be able to cancel the internal FB process before running the process ! Thanks Rob
Re: [firebird-support] Temporarily stop and disable garbage collection
On Thu, Apr 25, 2013 at 11:53 PM, Robert martin wrote: > > > ... a desire to > > maintain > > db_key stability or a misunderstanding of garbage collection. > > > > Hi > > Actually neither. We have a process where the system does an backup and > then restores back. The process actually renames the source DB file, > does the backup and then restores the backup with the initial file > name. We know that users are logged off because the application doing > the process is the server part of a client/server system. > > We have recently discovered this process sometimes fails because the > file is in use. My suspicion is that it is in use by the sweep process > (which I apparently been incorrectly referring to as garbage > collection). Although all applications have disconnected from the > database, the FDB file cannot be renamed. Stopping the FB service > allows a rename. > OK - the only safe thing to do is to shut down the server. My recollection is that the Firebird server keeps a database open for some period of time after the last connection closes to avoid the cost of reconnection in an environment where connections are short and frequent. Sorry to be so long in answering - life intervened Good luck, Ann [Non-text portions of this message have been removed]
Re: [firebird-support] Temporarily stop and disable garbage collection
> > OK - the only safe thing to do is to shut down the server. My recollection > is that the Firebird server keeps a database open for some period of time > after the last connection closes to avoid the cost of reconnection in an > environment where connections are short and frequent. > > Sorry to be so long in answering - life intervened > Hi No problem Ann. I appreciate your help with this ! I guess I will add that as an option to users experiencing the problem. The danger in shutting FB down is that any other databases that are in use will also be unavailable. What about the shutdown option offered in gFix. Would shutting a database down also cause FB to stop accessing it? Could I programmatically shutdown the database (how?) copy my file and then mark it back as online ? Cheers Rob
Re: [firebird-support] Temporarily stop and disable garbage collection
If you set garbage collection to zero. Installed a scheduled sweep when you know its a good time to do it and then do your back up well away from this sweep. Wouldn't you avoid this whole issue? Alan On 26/04/2013 7:54 AM, "Robert martin" wrote: > Hi > > We have a need to ensure garbage collection is not running in a given > database. Ideally we would stop / cancel any garbage collection in > progress, do our stuff, then turn garbage collection back on. > > Is this possible? > > Thanks > Rob > > > > > ++ > > Visit http://www.firebirdsql.org and click the Resources item > on the main (top) menu. Try Knowledgebase and FAQ links ! > > Also search the knowledgebases at http://www.ibphoenix.com > > ++ > Yahoo! Groups Links > > > > [Non-text portions of this message have been removed]
Re: [firebird-support] Temporarily stop and disable garbage collection
On 2/05/2013 10:36 a.m., Alan McDonald wrote: > > If you set garbage collection to zero. Installed a scheduled sweep > when you > know its a good time to do it and then do your back up well away from this > sweep. Wouldn't you avoid this whole issue? > Alan > Hi Alan Yes it might (and I may do that). However others have implied their is a difference between garbage collection and a sweep. Disabling a sweep might help but not fix the problem. Cheers Rob
