国产探花免费观看_亚洲丰满少妇自慰呻吟_97日韩有码在线_资源在线日韩欧美_一区二区精品毛片,辰东完美世界有声小说,欢乐颂第一季,yy玄幻小说排行榜完本

首頁 > 數(shù)據(jù)庫 > MySQL > 正文

mysql報(bào)錯(cuò):Deadlock found when trying to get lock; try restarting transaction的解決方法

2024-07-24 13:13:55
字體:
供稿:網(wǎng)友

發(fā)現(xiàn)問題

最近在補(bǔ)以前數(shù)據(jù)的時(shí)候程序突然報(bào)如下錯(cuò)誤:

[2017-02-10 13:12:06.678] [INFO] mysql/154562.html">mysqlLog - update tbl_playerdata_error: { [Error: ER_LOCK_DEADLOCK: Deadlock found when trying to get lock; try restarting transaction] code: 'ER_LOCK_DEADLOCK', errno: 1213, sqlState: '40001', index: 0 }

一看就是mysql出現(xiàn)了死鎖問題,其實(shí)上面跑的程序在測試服跑了好久都沒什么問題,為什么在正式服上會(huì)出現(xiàn)mysql的死鎖問題呢,第一反應(yīng)是不是數(shù)據(jù)量太大(3百多萬條),可是也不可能啊,再說死鎖和這些有什么雞毛的關(guān)系,看來要好好解決下了。

問題分析

我的分析是:由于現(xiàn)在處理的是正式服的數(shù)據(jù),而正式服還有許多用戶在操作,應(yīng)該是在用戶查詢,或者是其他操作的時(shí)候,和我這邊的數(shù)據(jù)更新產(chǎn)生了死鎖(首先說明使用的是:InnoDB存儲(chǔ)引擎。由于用戶那邊的查詢或者其他操作鎖定了我需要的資源,而我這邊更新也鎖定了用戶操作的一部分資源,兩邊都等著對方釋放資源,從而導(dǎo)致死鎖)。

解決方法

知道錯(cuò)誤code之后,先來查看mysql的說明,關(guān)于上面的 Error: 1213 SQLSTATE: 40001,參見:Server Error Codes and Messages

Message: Deadlock found when trying to get lock; try restarting transactionInnoDB reports this error when a transaction encounters a deadlock and is automatically rolled back so that your application can take corrective action. To recover from this error, run all the operations in this transaction again. A deadlock occurs when requests for locks arrive in inconsistent order between transactions. The transaction that was rolled back released all its locks, and the other transaction can now get all the locks it requested. Thus, when you re-run the transaction that was rolled back, it might have to wait for other transactions to complete, but typically the deadlock does not recur. If you encounter frequent deadlocks, make the sequence of locking operations (LOCK TABLES, SELECT ... FOR UPDATE, and so on) consistent between the different transactions or applications that experience the issue. See Section 14.8.5, “Deadlocks in InnoDB” for details.

上面有兩句:

To recover from this error, run all the operations in this transaction again<br><br>If you encounter frequent deadlocks, make the sequence of locking operations (<code class="literal">LOCK TABLES</code>, <code class="literal">SELECT ... FOR UPDATE</code>, and so on) <br>consistent between the different transactions or applications that experience the issue 

這兩句也就道出了處理死鎖的方法了,我就是在死鎖錯(cuò)誤發(fā)生的時(shí)候,使用定時(shí)器再重新做一次更新操作,這樣就避免了上面出現(xiàn)的問題。

另外,參考了stack overflow上面一個(gè)回答:http://stackoverflow.com/questions/2332768/how-to-avoid-mysql-deadlock-found-when-trying-to-get-lock-try-restarting-trans

One easy trick that can help with most deadlocks is sorting the operations in a specific order.You get a deadlock when two transactions are trying to lock two locks at opposite orders, ie:connection 1: locks key(1), locks key(2);connection 2: locks key(2), locks key(1);If both run at the same time, connection 1 will lock key(1), connection 2 will lock key(2) and each connection will wait for the other to release the key -> deadlock.Now, if you changed your queries such that the connections would lock the keys at the same order, ie:connection 1: locks key(1), locks key(2);connection 2: locks key(1), locks key(2);it will be impossible to get a deadlock.So this is what I suggest:Make sure you have no other queries that lock access more than one key at a time except for the delete statement. if you do (and I suspect you do), order their WHERE in (k1,k2,..kn) in ascending order.Fix your delete statement to work in ascending order:ChangeDELETE FROM onlineusers WHERE datetime <= now() - INTERVAL 900 SECONDToDELETE FROM onlineusers WHERE id IN (SELECT id FROM onlineusers WHERE datetime <= now() - INTERVAL 900 SECOND order by id) u;Another thing to keep in mind is that mysql documentation suggest that in case of a deadlock the client should retry automatically. you can add this logic to your client code. (Say, 3 retries on this particular error before giving up).

參考:http://blog.sina.com.cn/s/blog_4acbd39c01014gsq.html

總結(jié)

以上就是這篇文章的全部內(nèi)容了,希望本文的內(nèi)容對大家的學(xué)習(xí)或者工作能帶來一定的幫助,如果有疑問大家可以留言交流,謝謝大家對VeVb武林網(wǎng)的支持。


注:相關(guān)教程知識(shí)閱讀請移步到MYSQL教程頻道。
發(fā)表評論 共有條評論
用戶名: 密碼:
驗(yàn)證碼: 匿名發(fā)表
主站蜘蛛池模板: 平舆县| 尉犁县| 神农架林区| 镇坪县| 西乌珠穆沁旗| 安溪县| 周宁县| 汤原县| 吉首市| 汝城县| 卢氏县| 赤峰市| 衡水市| 甘谷县| 咸宁市| 弥勒县| 绥芬河市| 景德镇市| 白河县| 吉木萨尔县| 运城市| 三原县| 克什克腾旗| 思南县| 湛江市| 嘉禾县| 肃南| 安吉县| 湟源县| 宜兰县| 新巴尔虎左旗| 肥东县| 稻城县| 汶川县| 静海县| 澄江县| 萨嘎县| 广东省| 保定市| 长泰县| 金沙县|