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PC running slow?
You may have encountered an error message indicating a checksum operation on the pt table. Well, there are several ways to solve this problem, so we will do it in a moment.
One such tool is definitely pt-table-checksum, which works by dividing table rows into blocks of rows. The chunk size is dynamically changed during maintenance so as not to overload the server. pt-table-checksum includes a lot of security measures, including changing the block weight to ensure that queries run within the desired time frame.
NAME¶
OVERVIEW¶
Use¶
What is checksum table?
CHECKSUM TABLE reports the checksum of the contents of a table. You can use this directive to ensure that content is generally the same before and after a backup, restore, or other operation to return data to a known state. This statement inherits the SELECT privilege on the table.
pt-table-checksum performs a persistence check on online replication.Known checksum queries leading to different results for replicasit is not compatible with the master. Voluntary DSN indicates the masterMaster. The “INITIAL STATE” of the instrument is not equal to zero if imbalances are observed,or if warning errors occur.
How do I know if MySQL replicate is in sync?
The following command connects to the new replication master on the local host,An array of checksums, everything, and a report of the results for each uncovered replica:
This tool is designed to efficiently find data conflicts. Concerning interested partiesthe other one might solve the problem with pt-table-sync.
pt-table-checksum [OPTIONS] [DSN]
RISK¶
Percona Toolkit is designed, field tested and well tested.but all system tools can be dangerous for your system and database.dataServer. Please do the following before purchasing this tool:
DESCRIPTION¶
The default
pt-table-checksum is designed to work properly for just about everyone.Happening. When in doubt, use To --explain to see how the tool verifies the checksumDiagram. Here is a general criticism of how the function tool works.
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Unlike older versions of pt-table-checksum, this tool canone goal, and do not have much complexity or support for many otherschecksum techniques. It only performs checksum queries on one server, andthey go through replication to be re-executed on replicas. If you want oldbehavior, you can certainly use the Percona Toolkit version 1.0.
pt-table-checksum connects to the server you specify and finds lists of leads andTables corresponding to Filters you ordered (if applicable). Works one domain at a timetime, so it doesn’t require a lot of memory or an insane amount of workbefore the start of the checksum. This allows it to be used on very large servers. weused it on servers containing hundreds of thousands of game databases and tables, anda billion lines. Regardless of server size, pt-table-checksum worksexactly the same.
One of the reasons it can work on really good desks is because it separates each work surface.Blocks of rows and checksums, each followed by a block of one REPLACE..SELECT query.This resizes my fragment so checksum requests are made in the desired amount.time. The purpose of splitting tables is to end each tableThe only significant problem is to ensure that the checksums can be discrete and not causetoo much replication fails or loads the server. Hence the goalEach time block lasts 0.5 seconds by default.
InstThe tool constantly checks the speed at which the server can execute requests,and tweaks the details as it learns more about human server performance. Thisuses deliberate exponential averaging decay to keep the overall fragment size stable,however remain responsive if the server power buttons are on during checksum generationfor any reason. This means that the tool will quickly choke if youThe server is heavily loaded during another burst of traffic or a background task, for exampleexample.
How do I use PT Archiver?
Segmentation is definitely done with a technique that we otherwise call “nibble”.Tools with Percona Toolkit. This is the same procedure as with pt-archiver, for exampleExample. Legacy segmentation algorithms used in older versionspt-table-checksum removed because they just didn’t result in a predictable sizepiece and didn’t do well on many tables. Everything you need forA partitioned table is a kind of index (preferably a primary or unique key).Displaycel). When there is no clue, and the cube contains little enoughlines, the tool usually checks table a in a separate fragment.
pt-table-checksum has many other security measures to help avoid interference.with server operation, including replicas. To do it, we admit itpt-table-checksum is replicated and automatically connected to these types. (If thisfails, you can give a hint with the --recursion-method option.)
How do you use a PT-table-checksum?
To do this, pt-table-checksum recognizes replicas and connects to them automatically. (If that fails, you can also provide a hint with the –recursion-method option.) The tool constantly monitors replicas. If the replica is too far behind in the replication, pt-table-checksum pauses to resolve and catch up.
The program constantly monitors replicas. When the replica is too far behind pt-table-checksum inReplication, interrupts for boost. If the replicaan error is encountered, processing or stopping, pt-table-checksum pauses and waits. VIn addition, pt-table-checksum looks for common causes caused by problems such as:The replication filter refuses to work unless you force it. were replicationDangerous filters because queries that can run pt-table-checksummay conflict with them and subsequently cause replication to fail.
pt-table-checksum, which ensures that the bits are not too large to reliably check the checksummmm. Thisexecute an EXPLAIN query for each share and ignore chunks that can be largerthan the usual desired number of rows. You can adjust the sensitivity for thisprotect with this option --chunk-size-limit. There must be a tableInteger checksum as it gives you a small number of rowspt-table-checksum also shows the table is smallreplicas. This avoids the following scenario: The best table is empty on the master.but often very large on the replica and really in one big checksum query,which causes a very large replication delay.
There may be several other security measures. For example, pt-table-checksum could be a piece of furniture.innodb_lock_wait_timeout at session level of 1 second so when there is a lockWait, this will almost certainly be a victim rather than cause other requests to time out.Another protection checks the current load of the database server and aborts the load.also high. There wasn’t a single correct answer as to how long it would take, but Defaultpt-table-checksum will temporarily stop at this if it runs more than 25 times in a row.Interrogate. You should probably set a specific private value for your server via
Which command is used to verify the data consistency within replication streams in MySQL?
How do you use percona toolkit?
Step 1: Download the Percona repository file.Step 2: Install the Percona Collection Pack.Step 3: Always install Percona Toolkit on Ubuntu 20.04/18.04.
Pt 테이블의 체크섬 루틴을 수정했습니다.
Fixat Kontrollsummans Beteende För Pt-tabellen.
Comportamiento De Suma De Comprobación Fijo De La Tabla Pt.
Poprawiono Zachowanie Sum Kontrolnych Tabeli Pt.
Corretto Il Comportamento Del Checksum Del Lettino Riabilitativo.
Исправлена контрольная сумма таблицы Pt.
Corrigido O Comportamento Da Soma De Verificação Para A Tabela Pt.
Vast Gedrag Van Controlesom Van Revalidatietabel.
Prüfsummenverhalten Der Therapeutentabelle Korrigiert.
Routines De Somme De Contrôle Fixes De La Table Pt.
