Database Replay, Part 1 Database. Journal. com. Synopsis. Oracle DBAs have long wished to be able to capture applications workloads in a production environment and then replay that workload against a test environment to determine the impact of proposed database or application changes on database performance. Oracle Database 1. R1s new Database Replay feature enables an Oracle DBA to capture, massage, and then replay workloads either selectively or in their entirety across a wide range of database environments and platforms. This article provides a primer for using Oracle 1. Database Replay to effectively predict the performance of rapidly changing applications within increasingly fluid database environments. Oracle offers a comprehensive and fully integrated stack of cloud applications and platform services. The Installation is divided into 3 main categories Preinstallation task. Game Resident Evil 3 Pc. Installation of Oracle 11g R2 Grid Infrastructure 11. If my time served in information technology has taught me anything, its the utter truth behind Murphys Law Anything that can go wrong will go wrong. Over the years, Ive also learned the veracity of several corollaries to Murphys Law, including the fact that interchangeable parts wont and especially the rejoinder that Murphy was actually an optimist. I hope to add my own corollary to these grim testimonials one day with the following observation obtained at great pain Nothing works in production like it does in the test environment. All attempts at ill humor aside, Oracle DBAs face a severe challenge on a regular basis to predict accurately how the next set of changes to the databases application code, database patch set, or hardware configuration will affect negatively the entire database environment. When I say the entire environment, I do mean that literally every SQL statement that any running application has executed, regardless if its just a simple query or a complex batch job that issues a huge volume of DML statements, must be captured. This challenge has become even more acute because todays typical application workloads are generated across a landscape that spans myriad technologies n tier application servers, web farms, and even client server legacy applications. Moreover, when an application appears to be performing poorly, the root cause of a detected performance issue is often nearly impossible to track down it may be the indirect result of an incorrect network configuration, the application servers configuration, or even the application clients environment variable settings. The only chance to accomplish this lofty yet crucial goal is via an application workload capture and playback product suite. This type of application is specifically designed to capture the complete workload thats been executed against the current production database environment P0 and then play back precisely that same workload against the next iteration of the production environment P1. However, my past experience has shown this means asking upper management to open the company checkbook to purchase a relatively expensive third party solution e. HPs Load. Runner tool. The cost of licensing this software, the cost of procuring and configuring the servers it runs upon, and most especially the manpower expense to configure and prove out the capture and playback suite even before workloads can be captured and replayed may easily run into the six figure USD range. And thats why many IT organizations have surrendered to the perception that its simply impossible to test for application system regression in a cost effective manner. Beyond Performance Regression. My prior article series about Oracle Database 1. SQL statement performance tuning features SQL Performance Analyzer SPA and SQL Plan Management SPM discussed how Oracle 1. Options and Packs. This chapter describes the separately licensed Oracle Database options, management packs, and other products you can purchase to enhance the. Joule Softair. BR5eH_hfAQ8/T9T7w7hbrSI/AAAAAAAAAQs/3lLMAYWjSUM/image_thumb8.png?imgmax=800' alt='Oracle 11G Patch Level' title='Oracle 11G Patch Level' />DBA to easily isolate SQL statements whose performance has either progressed, remained unchanged, or regressed after the application environment has been changed. Any robust capture and playback suite must certainly capture and compare the differences between the original P0 versus the future P1 system, application, and database performance statistics, especially SQL statements that are now performing dramatically worse. However, there are two other types of regression that any robust capture and playback suite needs to address as well Error Regression. UaFuEkweIjs/TaMo-plGxfI/AAAAAAAAAkk/KtXLwNA1AXI/s1600/2_soa_11.1.1.3.0_patchIns.JPG' alt='Oracle 11G Patch Level' title='Oracle 11G Patch Level' />When a captured workload is being played back, its not unusual to encounter errors, and in fact this is almost certainly a desirable outcome. For example, Id like to verify that an expected exception like the violation of referential integrity i. CHECK, or NOT NULL constraint actually arises and is trapped correctly. Oracle 11G Patch Level' title='Oracle 11G Patch Level' />Also, Id like to insure that an appropriate and expected exception is raised whenever a crucial business rule is violated. For example, if during payroll check processing an employees net salary doesnt balance to gross pay less all deductions, Id like that exception to be trapped as an error. Therefore, any robust capture and playback suite must be capable of monitoring three types of error regression Have all expected errors occurred Next, have any error conditions been raised that were not expected This obviously indicates that severe error regression is possible because of system or application changes. Finally, have any expected errors not occurred This condition is much more subtle, because it indicates that something sinister has changed within the system or application, and crucial business rules are either being misapplied or not applied at all. Data Regression. Any robust capture and playback suite also must pay strict attention to any variance in the data itself after the playback has completed. For example, if Im testing a mission critical financial system, I must insure that the identical financial transactions have completed in the appropriate order and all accounts total to the same balances in the P1 environment as they would in the P0 environment. If I dont receive identical results, I must assume that something in my application, database, or environment has changed to prevent a perfect playback. Another crucial feature of the capture and playback suite It must be able to insure that the captured workload is played back against the P1 environment only after that environment has been reset to reflect the state of the P0 environment at the time workload capture was initiated. Otherwise, theres a chance that false positive indications of data regression will be detected that have nothing to do with changes to the application, database, or environment. The metaphor of a player piano roll especially appeals to me when I imagine how a workloads individual, dependent transactions need to be captured and then played back Once the pianist has finished playing a piece of music, the piano roll has not only captured the exact notes performed, but also the exact frequency at which individual keys were struck. In essence, it gave the listener an exact duplicate that encapsulates the maestros playing style, including all of her performances subtle pauses. Humorous aside to readers younger than 2. If youve never seen a player piano roll, please substitute MP3 or even WAV file or ask one of your older co workers to explain how things were back in the old days. Database Replay Features Summary. Thankfully, Oracle 1. Database Replay DBR suite offers all of the features Ive just described. DBR permits an Oracle DBA to Capture a workload thats being generated on a production database system. Oracle 1. 1g RAC Interview question and answers. Well, there is not much difference between 1. R 1 RAC. But there is a significant difference in 1. R2. Prior to 1. 1g. R11. 0g RAC, the following were managed by Oracle CRSDatabases. Instances. Applications. Node Monitoring. Event Services. High Availability. From 1. 1g. R2onwards its completed HA stack managing and providing the following resources as like the other cluster software like VCS etc. Databases. Instances. Applications. Cluster Management. Node Management. Event Services. High Availability. Core Ftp Pro 2 2 Serial Port. Network Management provides DNSGNSMDNSD services on behalf of other traditional services and SCAN Single Access Client Naming method, HAIPStorage Management with help of ASM and other new ACFS filesystemTime synchronization rather depending upon traditional NTPRemoved OS dependent hang checker etc, manages with own additional monitor process. What are Oracle Cluster ComponentsCluster Interconnect HAIP. Shared Storage OCRVoting Disk. Clusterware software. VIP, Node apps etc. What are Oracle Kernel Components nothing but how does Oracle RAC database differs than Normal single instance database in terms of Binaries and process. Basically Oracle kernel need to switched on with RAC On option when you convert to RAC, that is the difference as it facilitates few RAC bg process like LMON,LCK,LMD,LMS etc. To turn on RAC link the oracle libraries cd ORACLEHOMErdbmslib make f insrdbms. ORACLEHOMEbin relink oracle. Oracle RAC is composed of two or more database instances. They are composed of Memory structures and background processes same as the single instance database. Oracle RAC instances use two processes GESGlobal Enqueue Service, GCSGlobal Cache Service that enable cache fusion. Oracle RAC instances are composed of following background processes. ACMSAtomic Controlfile to Memory Service ACMSGTX0 jGlobal Transaction Process. LMONGlobal Enqueue Service Monitor. LMDGlobal Enqueue Service Daemon. LMSGlobal Cache Service Process. LCK0Instance Enqueue Process. RMSnOracle RAC Management Processes RMSnRSMNRemote Slave Monitor. What is Clusterware Software that provides various interfaces and services for a cluster. Typically, this includes capabilities that Allow the cluster to be managed as a whole. Protect the integrity of the cluster. Maintain a registry of resources across the cluster. Deal with changes to the cluster. Provide a common view of resources. What are the background process that exists in 1. Process Name. FunctionalitycrsdThe CRS daemon crsd manages cluster resources based on configuration information that is stored in Oracle Cluster Registry OCR for each resource. This includes start, stop, monitor, and failover operations. The crsd process generates events when the status of a resource changes. Cluster Synchronization Service CSS Manages the cluster configuration by controlling which nodes are members of the cluster and by notifying members when a node joins or leaves the cluster. If you are using certified third party clusterware, then CSS processes interfaces with your clusterware to manage node membership information. CSS has three separate processes the CSS daemon ocssd, the CSS Agent cssdagent, and the CSS Monitor cssdmonitor. The cssdagent process monitors the cluster and provides inputoutput fencing. This service formerly was provided by Oracle Process Monitor daemon oprocd, also known as Ora. Fence. Service on Windows. A cssdagent failure results in Oracle Clusterware restarting the node. Disk Monitor daemon diskmon Monitors and performs inputoutput fencing for Oracle Exadata Storage Server. As Exadata storage can be added to any Oracle RAC node at any point in time, the diskmon daemon is always started when ocssd is started. Event Manager EVM Is a background process that publishes Oracle Clusterware eventsmdnsdMulticast domain name service m. DNS Allows DNS requests. The m. DNS process is a background process on Linux and UNIX, and a service on Windows. Oracle Grid Naming Service GNS Is a gateway between the cluster m. DNS and external DNS servers. The GNS process performs name resolution within the cluster. Oracle Notification Service ONS Is a publish and subscribe service for communicating Fast Application Notification FAN eventsoraagentoraagent Extends clusterware to support Oracle specific requirements and complex resources. It runs server callout scripts when FAN events occur. This process was known as RACG in Oracle Clusterware 1. Release 1 1. 1. 1. Oracle root agent orarootagent Is a specialized oraagent process that helps CRSD manage resources owned by root, such as the network, and the Grid virtual IP addressoclskdCluster kill daemon oclskd Handles instancenode evictions requests that have been escalated to CSSgipcdGrid IPC daemon gipcd Is a helper daemon for the communications infrastructurectssdCluster time synchronisation daemonctssd to manage the time syncrhonization between nodes, rather depending on NTP7. Under which user or owner the process will start Component. Name of the Process. Owner. Oracle High Availability Serviceohasdinit, root. Cluster Ready Service CRSCluster Ready Servicesroot. Cluster Synchronization Service CSSocssd,cssd monitor, cssdagentgrid owner. Event Manager EVMevmd, evmloggergrid owner. Cluster Time Synchronization Service CTSSoctssdroot. Oracle Notification Service ONSons, eonsgrid owner. Oracle Agentoragentgrid owner. Oracle Root Agentorarootagentroot. Grid Naming Service GNSgnsdroot. Grid Plug and Play GPn. Pgpnpdgrid owner. Multicast domain name service m. DNSmdnsdgrid owner. As you said Voting OCR Disk resides in ASM Diskgroups, but as per startup sequence OCSSD starts first before than ASM, how is it possibleHow does OCSSD starts if voting disk OCR resides in ASM Diskgroups You might wonder how CSSD, which is required to start the clustered ASM instance, can be started if voting disks are stored in ASM This sounds like a chicken and egg problem without access to the voting disks there is no CSS, hence the node cannot join the cluster. But without being part of the cluster, CSSD cannot start the ASM instance. To solve this problem the ASM disk headers have new metadata in 1. ASM disk containing a voting disk. The kfdhdb. vfstart and kfdhdb. CSS where to find the voting file. This does not require the ASM instance to be up. Once the voting disks are located, CSS can access them and joins the cluster. How does SCAN works Client Connected through SCAN name of the cluster remember all three IP addresses round robin resolves to same Host name SCAN Name, here in this case our scan name is cluster. The request reaches to DNS server in your corp and then resolves to one of the node out of three. If GNS Grid Naming service or domain is configured that is a subdomain configured in  the DNS entry for to resolve cluster address the request will be handover to GNS gnsdHere in our case assume there is no GNS, now the with the help of SCAN listeners where end points are configured to database listener. Database Listeners listen the request and then process further. In case of node addition, Listener 4, client need not to know or need not change any thing from their tns entry address of 4th nodeinstance as they just using scan IP. Same case even in the node deletion.