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I. OverviewWhen we consider the high-availability architecture of the MySQL database, we mainly consider the following aspects: If the database is down or an unexpected outage, and so on, can restore the availability of the database as soon as possible to reduce downtime, to ensure that the business will not be interrupted due to database failure. Data for non-primary nodes that are used as backups, read replicas, and so on, should be in

phenomenon.A. The time between the end of the commit and the DBWR process is short, and if it happens after commit, the DBWR does not end before the power outage, becauseThe data after commit is already part of the data file, but this part of the file is not fully written to the data file. So you need to roll forward. ByinCommit has triggered LGWR that all changes that have not yet been written to the data file will be restarted by the Smon process b

Tags: technology share GIC binary run new feature keepalive enable ADF receiveOriginal address Author Introduction Wang Songlei, currently serving in Ucloud, is engaged in the MySQL database core research and development work. Mainly responsible for Ucloud cloud database UDB kernel Troubleshooting and new features of the database research and development work. I. Overview When we consider the high-availability architecture of the MySQL database, we mainly consider the following aspects:

in the relay log file and parse it into concrete operation to achieve the same master-slave operation, and the final data is consistent;Problems and Solutions Problems with MySQL master-slave replication: Data may be lost after a main library outage There is only one SQL Thread from the library, the main library write pressure is high, replication is likely to delay Workaround: Semi-synchronous Replication---resolve d

Chapter 1th IntroductionWith the widespread popularization of Internet application, the storage and access of massive data has become the bottleneck problem of system design. For a large-scale Internet application, billions of of PV per day is undoubtedly a very high load on the database. The stability and scalability of the system caused great problems. With data slicing to improve site performance, scaling out the data layer has become the preferred way for architects to develop. Hori

file and parse it into concrete operation to achieve the same master-slave operation, and the final data is consistent;Problems and SolutionsProblems with MySQL master-slave replication: Data may be lost after a main library outage There is only one SQL Thread from the library, the main library write pressure is high, replication is likely to delay Workaround: Semi-synchronous Replication---resolve data loss issues Para

The service provider registers its services with the registry and reports the call time to the Monitoring center, which does not include network overhead The service consumer obtains the service provider address list from the registry and invokes the provider directly based on the load algorithm, reporting the call time to the Monitoring center, which includes the network overhead Registration Center, service provider, service consumers are long connections between the three, except the monitor

Excerpt: http://blog.csdn.net/shuaihj/article/details/14163713-----------------------------------------------------------acid refers to four basic elements of database transactions that are performed correctly: Atomicity (atomicity), Consistency ( Consistency), isolation (isolation), persistence (durability).1. Atomic NatureAtomicity means that a transaction is a non-divisible unit of work, and the operations in the transaction either occur or do not occur. A. Case A to B transfer 100 Yuan Money

Tags: exception rationale schema query distribution href character request portChapter 1th IntroductionWith the widespread popularization of Internet application, the storage and access of massive data has become the bottleneck problem of system design. For a large-scale Internet application, billions of of PV per day is undoubtedly a very high load on the database. The stability and scalability of the system caused great problems. With data slicing to improve site performance, scaling out the d

1. OverviewWhen we consider the highly available architecture of the MySQL database, we mainly consider the following aspects: If the database is down or an unexpected outage, and so on, can restore the availability of the database as soon as possible to reduce downtime, to ensure that the business will not be interrupted due to database failure. Data for non-primary nodes that are used as backups, read replicas, and so on, should be in r

database: Can reduce the load of a single machine, while minimizing the loss caused by downtime; Load balancing strategy: can reduce the access load of a single machine, reduce the possibility of downtime; Cluster Solution: Solves the problem that the single point database can not be accessed by the database outage; Read and write separation strategy: maximize the speed and concurrency of reading data in the application; 2nd Chapter

file does not require seek, even if the log contains incomplete commands for some reason (such as a write-in disk full, write-down, etc.), The Redis-check-aof tool can also easily fix this problem. Redis can automatically override AOF in the background when the AOF file volume becomes too large: The rewritten new AOF file contains the minimum set of commands required to restore the current dataset. The entire rewrite operation is absolutely secure, as Redis will continue to append commands to

Long time not to come here to write things, a bit of today, come here to write something recently encountered. Some time ago, a telecommunications business users due to a core production library several times the recent outage restart, multi-personnel involved in the fruitless, sent me an email, probably meaning that now the problem has caused more serious consequences, hoping to help intervene in the analysis, diagnosis and solve the problem. By the

Fsync each time you execute a write command. The default policy for AOF is Fsync once per second, in which Redis can still maintain good performance and, even if there is a failure, it will lose at most one second of data (Fsync will execute in a background thread, so the main thread can continue to work on the command request). The AOF file is an append-only log file (append only), so the write to the AOF file does not require seek, even if the log contains incomplete commands for some reason

First, look at the high-availability scenarios for common MySQL:Description of the pair:1) heartbeat through the serial line or Ethernet network cable directly connected to the end of the service to do health checks, and is responsible for the implementation of DRBD,MYSQL,VIP and other resources automatic switching.2) Data-1-2 as a data-1-1 high-usable hot sub, under normal circumstances data-1-1 provide a partition SDB1 for MySQL to use.3) physical disks are RAID10 or RAID0, and are selected ba

Label:Disclaimer: This text is reproduced (non-original), the article analysis is very thorough, has added the original link, if there are any infringement issues, please inform, I will immediately delete. Chapter 1th IntroductionWith the widespread popularization of Internet application, the storage and access of massive data has become the bottleneck problem of system design. For a large-scale Internet application, billions of of PV per day is undoubtedly a very high load on the database. The

First, EXT2 and EXT3The file system that was used by default in Linux before is Ext2,ext2 file system is really efficient and stable. However, with the application of Linux system in the key business, the weakness of Linux file system is gradually revealed: the Ext2 file system which the system uses by default is a non-log file system. This application in key industries is a deadly weakness. The Ext3 file system is developed directly from the Ext2 file system, and the current Ext3 file system is

. Often generated by the computer peripherals or some interface functions, such as keyboards, printers, serial ports, etc. this type of interrupt can be blocked or ignored by the software when the CPU is handling other emergency operations. For example, if the printer is interrupted, the CPU can respond faster or slower to the printer interrupt request, because it is perfectly reasonable to have the printer wait a little longer.Non-shielded interrupts. Caused by an unexpected event, such as powe

, service provider, service consumers are long connections between the three, except the monitoring centerThe registry will immediately push events to inform consumers of the presence of a long-connected-aware service provider, service provider downtimeThe Registry and Monitoring Center are all down, without impacting the already running providers and consumers, who cache the provider list locallyRegistries and monitoring centers are optional and service consumers can connect directly to service

, service provider, service consumers are long connections between the three, except the monitoring centerThe registry will immediately push events to inform consumers of the presence of a long-connected-aware service provider, service provider downtimeThe Registry and Monitoring Center are all down, without impacting the already running providers and consumers, who cache the provider list locallyRegistries and monitoring centers are optional and service consumers can connect directly to service