Log Shipping Essay Research Paper The concept free essay sample

Log Shipping Essay, Research Paper The construct of standby waiters is non a new one. It has been around a long clip and been used by many DBAs. Traditionally, utilizing a standby waiter for failover has involved manually doing database and log backups on the production waiter and so reconstructing them to the standby waiter on a regular footing. This manner, should the production waiter fail, so users could entree the standby waiter alternatively, and downtime and informations loss would be minimized. What is Log Transporting Basically, log transportation is the procedure of automatizing the backup of database and dealing log files on a production SQL waiter, and so reconstructing them onto a standby waiter. This in consequence keeps the two SQL Servers in # 8220 ; synch # 8221 ; . Problems with Log Transporting log transportation is a via media. It is non the ideal solution, but it is frequently a practical solution given real-world budget restraints. Some of the jobs with log transporting include: + Log transportation failover is non automatic. The DBA must still manually failover the waiter, which means the DBA must be present when the failover occurs. + The users will see some downtime. How long depends on how good you implemented log transportation, the nature of the production waiter failure, your web, the standby waiter, and the application or applications to be failed over. + Some informations can be lost, although non ever. How much information is lost depends on how frequently you schedule log transportation and whether or non the dealing log on the failed production waiter is recoverable. + The database or databases that are being failed over to the standby waiter can non be used for anything else. But databases on the standby waiter non being used for failover can still be used usually. + When it comes clip for the existent failover, you must make one of two things to do your applications work: either rename the standby server the same name as the failed production waiter ( and the IP reference ) , or re-point your user # 8217 ; s applications to the new standby waiter. In some instances, neither of these options is practical. Log Transporting with SQL Server 7.0 In the yesteryear, SQL Server developers and DBAs have had to make customized books to implement log transportation. But with SQL Server 7.0, Microsoft provided undocumented maulerss into the drawn-out stored process xp_sqlmaint to assist automatize log transportation. The Microsoft BackOffice 4.5 Resource Kit ( BORK ) Log Transporting public-service corporation consists of books and instructions that use these maulerss into xp_sqlmaint for making a largely automated log-shipping solution. You can acquire BORK from Microsoft Press for $ 250 retail ( about $ 130 street monetary value ) . Microsoft developed the BORK Log Shipping public-service corporation, as it did all its resource kit public-service corporations, for internal usage at Microsoft ; Microsoft Product Support doesn # 8217 ; t back up the public-service corporation. And you # 8217 ; ll happen the BORK Log Shipping public-service corporation rough around the borders. Although it automates much of the log-shipping procedure, the public-service corporation requires a just sum of manual apparatus and disposal. However, SQL Server 2000 Enterprise Edition to the full supports lo g transportation and provides a more polished interface than the BORK public-service corporation. In a log-shipping execution, neglecting over to the standby waiter is a manual procedure. If you require automated failover, a better solution is Microsoft Cluster Services ( MSCS ) , which automatically fails over one bunch node to another bunch node. However, the constellating solution costs more than log transportation, requires extra specialised hardware, and forces a closer yoke, or dependence, of primary and secondary waiters. To put up log transportation, all you need is the BORK public-service corporation, adequate disc infinite on your production and standby waiters to hive away the database and dealing log backup files, and a web connexion between the waiters. Log Transporting with SQL Server 2000 SQL Server 2000 Enterprise Edition to the full supports log transporting apparatus and monitoring. The Enterprise Edition # 8217 ; s Database Maintenance Plan Wizard includes a cheque box on the Transaction Log Backup duologue box that lets you stipulate transporting the log to another waiter. To utilize this option, you must first set up file portions on the beginning and finish waiters for the dealing log booklets. The ace will so execute the full database backup and restore, create the dealing log backup occupation, and make the occupations on the finish waiter that transcript and burden the backups. As with the Microsoft BackOffice 4.5 Resource Kit ( BORK ) Log Shipping public-service corporation for SQL Server 7.0, these log-shipping occupations call the xp_sqlmaint extended stored process to execute their undertakings. The ace besides creates watchful occupations for the transcript and burden operations ; these occupations call the same monitoring stored processs as the BORK public-service corporation calls. However, the stored processs and tabular arraies underlying SQL Server 2000 # 8217 ; s log-shipping functionality differ from and hold more consistent names than the stored processs and tabular arraies that provide the BORK functionality. SQL Server 2000 has seven tabular arraies to BORK # 8217 ; s three and has four stored processs for monitoring. Overall, the SQL Server 2000 system is more polished than the BORK version. With SQL Server 2000, you can supervise log transportation through the Enterprise Manager alternatively of through the stored processs. When you set up log transportation, the Database Maintenance Plan Wizard places a Log Shipping Monitor in the Management node of the waiter you specify. This proctor consists of a Tab duologue box that lets you observe log transportation # 8217 ; s position and alteration scenes for the beginning and finish waiters. You can besides see transcript and burden histories by right-clicking the Log Shipping Monitor in the inside informations window glass. Like SQL Server 7.0, SQL Server 2000 doesn # 8217 ; t offer machine-controlled support for failover or for altering the waiters # 8217 ; functions so that log transportation goes the other way. Alternatively, SQL Server 2000 supplies four stored processs to help in the failover procedure and relies on a new constitutional Data Transformation Services ( DTS ) characteristic to reassign logins from the beginning to the finish waiter. You can utilize the stored processs to decide the logins on the former standby waiter, to alter the waiters # 8217 ; functions, and even to alter which server the Log Shipping Monitor resides on.