RE: Multimaster replication as alternative backup
Simple,Clear and Superb explanation. Thanks Arup. -Original Message- Nanda Sent: Wednesday, November 19, 2003 1:10 AM To: Multiple recipients of list ORACLE-L VirVit, You haven't specified Oracle version and your tolerance for data loss. If you can afford to lose the data in the most current redo log file, then I would suggest 9i Data Guard in maximum performance mode (or Standby in 8i) solution over the MM replication. The DG solution does not affect the primary database performance. You can backup the standby database and use it for recovery of the primary, too. If you can't afford to lose any data, then you can still use the DG Maximum Protection (in 9i) mode, but it will affect the performance to some extent. However, in this case (no data loss) you have to enable MM Synchronous Replication as opposed to the default Asynchronous mode. In the Synch mode, the performance is worse compared to the Max Protection DG solution. Here is a summary of the options: Oracle 8i | +-> Last redo data loss ok => Standby Database ~~ Performance=BEST +-> LAst redo data los NOT ok => MM Synchronous Replication ~~ Performance=VERY BAD Oracle 9i | +-> Last redo data loss ok => Data Guard Max Performance Mode ~~ Performance=BEST +-> LAst redo data los NOT ok => | +-> Option 1: MM Synchronous Replication ~~ Performance=VERY BAD +-> Option 2: Data Guard Max Protection Mode ~~ Performance=BAD Therefore, you are better off using DG (or standby in 8i). Pros: (1) You can use standby datafiles to recover primary database (2) You can take RMAN backups from the standby, reducing the CPU cycle requirements in primary Cons: (1) In Max Protection Mode, the primary also halts if the standby has a problem; not truly a HA solution. Ideally you need three or more servers - one primary and two standbys to work perfectly => high cost Summary: If your management can live with the loss of the last redo, your best option is DG Max Performance (or Standby, in 8i), IMHO. HTH. Arup Nanda www.proligence.com - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Tuesday, November 18, 2003 11:54 PM > Hello! > > What do you think of additional backup method as multimaster replication? > Isn't it a way to continue working normal, if main database crash and I move > all connections to another master site? > > -- > Oracle 9i DBA beginner > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: VirVit > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Arup Nanda INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Sami INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Multimaster replication as alternative backup
Verification was easy. We just powered down the primary machine, changed the db name in the external table, drop the replication on the backup server and restart the application. Everything worked fine. After 2-3 days, over the weekend, we rebuilt the replication again. Yechiel Adar Mehish - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Wednesday, November 19, 2003 8:00 PM > Yechiel - So how do you verify your backup environment? My gut feeling is > that simpler systems are less prone to catastrophe, and multimaster > replication definitely adds a lot of pieces compared to conventional > backups. > > Dennis Williams > DBA > Lifetouch, Inc. > [EMAIL PROTECTED] > > -Original Message- > Sent: Wednesday, November 19, 2003 11:05 AM > To: Multiple recipients of list ORACLE-L > > > We are doing exactly that. We use multi master synchronous replication. In > case the regular server dies, we drop replication from the backup machine. > Change one parameter in the application ini file (what db name to use in > connections), start the application again. About 5 minutes turn around time. > Use it only if you have high speed connection and the servers are close. It > adds about 10% overhead to the application. It depends on the amount of > updates vs. selects of the application. > > Yechiel Adar > Mehish > - Original Message - > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Wednesday, November 19, 2003 6:54 AM > > > > Hello! > > > > What do you think of additional backup method as multimaster replication? > > Isn't it a way to continue working normal, if main database crash and I > move > > all connections to another master site? > > > > -- > > Oracle 9i DBA beginner > > > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: VirVit > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > > San Diego, California-- Mailing list and web hosting services > > - > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Yechiel Adar > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: DENNIS WILLIAMS > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Yechiel Adar INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: Multimaster replication as alternative backup
Yechiel - So how do you verify your backup environment? My gut feeling is that simpler systems are less prone to catastrophe, and multimaster replication definitely adds a lot of pieces compared to conventional backups. Dennis Williams DBA Lifetouch, Inc. [EMAIL PROTECTED] -Original Message- Sent: Wednesday, November 19, 2003 11:05 AM To: Multiple recipients of list ORACLE-L We are doing exactly that. We use multi master synchronous replication. In case the regular server dies, we drop replication from the backup machine. Change one parameter in the application ini file (what db name to use in connections), start the application again. About 5 minutes turn around time. Use it only if you have high speed connection and the servers are close. It adds about 10% overhead to the application. It depends on the amount of updates vs. selects of the application. Yechiel Adar Mehish - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Wednesday, November 19, 2003 6:54 AM > Hello! > > What do you think of additional backup method as multimaster replication? > Isn't it a way to continue working normal, if main database crash and I move > all connections to another master site? > > -- > Oracle 9i DBA beginner > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: VirVit > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Yechiel Adar INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: DENNIS WILLIAMS INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Multimaster replication as alternative backup
We are doing exactly that. We use multi master synchronous replication. In case the regular server dies, we drop replication from the backup machine. Change one parameter in the application ini file (what db name to use in connections), start the application again. About 5 minutes turn around time. Use it only if you have high speed connection and the servers are close. It adds about 10% overhead to the application. It depends on the amount of updates vs. selects of the application. Yechiel Adar Mehish - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Wednesday, November 19, 2003 6:54 AM > Hello! > > What do you think of additional backup method as multimaster replication? > Isn't it a way to continue working normal, if main database crash and I move > all connections to another master site? > > -- > Oracle 9i DBA beginner > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: VirVit > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Yechiel Adar INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: Multimaster replication as alternative backup
VirVit, You haven't specified Oracle version and your tolerance for data loss. If you can afford to lose the data in the most current redo log file, then I would suggest 9i Data Guard in maximum performance mode (or Standby in 8i) solution over the MM replication. The DG solution does not affect the primary database performance. You can backup the standby database and use it for recovery of the primary, too. If you can't afford to lose any data, then you can still use the DG Maximum Protection (in 9i) mode, but it will affect the performance to some extent. However, in this case (no data loss) you have to enable MM Synchronous Replication as opposed to the default Asynchronous mode. In the Synch mode, the performance is worse compared to the Max Protection DG solution. Here is a summary of the options: Oracle 8i | +-> Last redo data loss ok => Standby Database ~~ Performance=BEST +-> LAst redo data los NOT ok => MM Synchronous Replication ~~ Performance=VERY BAD Oracle 9i | +-> Last redo data loss ok => Data Guard Max Performance Mode ~~ Performance=BEST +-> LAst redo data los NOT ok => | +-> Option 1: MM Synchronous Replication ~~ Performance=VERY BAD +-> Option 2: Data Guard Max Protection Mode ~~ Performance=BAD Therefore, you are better off using DG (or standby in 8i). Pros: (1) You can use standby datafiles to recover primary database (2) You can take RMAN backups from the standby, reducing the CPU cycle requirements in primary Cons: (1) In Max Protection Mode, the primary also halts if the standby has a problem; not truly a HA solution. Ideally you need three or more servers - one primary and two standbys to work perfectly => high cost Summary: If your management can live with the loss of the last redo, your best option is DG Max Performance (or Standby, in 8i), IMHO. HTH. Arup Nanda www.proligence.com - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Tuesday, November 18, 2003 11:54 PM > Hello! > > What do you think of additional backup method as multimaster replication? > Isn't it a way to continue working normal, if main database crash and I move > all connections to another master site? > > -- > Oracle 9i DBA beginner > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: VirVit > INET: [EMAIL PROTECTED] > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com > San Diego, California-- Mailing list and web hosting services > - > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Arup Nanda INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Multimaster replication as alternative backup
Hello! What do you think of additional backup method as multimaster replication? Isn't it a way to continue working normal, if main database crash and I move all connections to another master site? -- Oracle 9i DBA beginner -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: VirVit INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
