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現在、私の Web サイトで次のエラー メッセージが表示されます: Error establishing a database connection。/phpma にアクセスすると、次のメッセージが表示されます#1040 - Too many connections。

を再起動mysqldすると、問題は一時的に解消されます。

残念ながら、それは現在3回戻ってきました。

私の専用ボックスもメモリが 8Gb から 1Gb 未満に減っています。

Total Memory    8181984 kB
Free Memory 99344 kB
Total Swap Memory   1051064
kB Free Swap Memory 0 kB

mysqlサーバーにアクセスして を実行するSHOW PROCESSLISTと、次の情報が表示されます。

| 17181 | my_db | localhost | my_db | Query   | 35117 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'boraras-brigittae' AND wp_po |
| 17182 | my_db | localhost | my_db | Query   | 35118 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17183 | my_db | localhost | my_db | Query   | 35117 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'boraras-brigittae' AND wp_po |
| 17184 | my_db | localhost | my_db | Query   | 35117 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'boraras-brigittae' AND wp_po |
| 17185 | my_db | localhost | my_db | Query   | 35041 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'akysis-vespa' AND wp_posts.p |
| 17186 | my_db | localhost | my_db | Query   | 35050 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('images','profiledotline-gif') A |
| 17187 | my_db | localhost | my_db | Query   | 35050 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('images','picarrow-gif') AND (po |
| 17188 | my_db | localhost | my_db | Query   | 35043 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17189 | my_db | localhost | my_db | Query   | 35041 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('m','marginal') AND (post_type = |
| 17190 | my_db | localhost | my_db | Query   | 34989 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17191 | my_db | localhost | my_db | Query   | 34989 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('w','wet-dry-filter') AND (post_ |
| 17192 | my_db | localhost | my_db | Query   | 34990 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17193 | my_db | localhost | my_db | Query   | 34954 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'corydoras-sterbai' AND wp_po |
| 17194 | my_db | localhost | my_db | Query   | 34954 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17195 | my_db | localhost | my_db | Query   | 34955 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17196 | my_db | localhost | my_db | Query   | 34954 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17197 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17198 | my_db | localhost | my_db | Query   | 34955 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17199 | my_db | localhost | my_db | Query   | 34898 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17200 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17201 | my_db | localhost | my_db | Query   | 34898 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums','lofiversion','index-ph |
| 17202 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17204 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17205 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'sawbwa-resplendens' AND wp_p |
| 17206 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'badis-sp-buxar' AND wp_posts |
| 17207 | my_db | localhost | my_db | Query   | 34898 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'melanotaenia-boesemani' AND  |
| 17208 | my_db | localhost | my_db | Query   | 34898 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'betta-prima' AND wp_posts.po |
| 17209 | my_db | localhost | my_db | Query   | 34865 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17210 | my_db | localhost | my_db | Query   | 34897 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17211 | my_db | localhost | my_db | Query   | 34898 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17213 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17214 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17215 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('knowledge-base') AND (post_type |
| 17216 | my_db | localhost | my_db | Query   | 34865 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17217 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17218 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'badis-sp-buxar' AND wp_posts |
| 17219 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums','lofiversion','index-ph |
| 17220 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'betta-prima' AND wp_posts.po |
| 17221 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17222 | my_db | localhost | my_db | Query   | 34865 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17223 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17224 | my_db | localhost | my_db | Query   | 34865 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'hemichromis-lifalili' AND wp |
| 17225 | my_db | localhost | my_db | Query   | 34864 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17226 | my_db | localhost | my_db | Query   | 34862 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'apistogramma-borellii' AND w |
| 17227 | my_db | localhost | my_db | Query   | 34863 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'melanotaenia-lacustris' AND  |
| 17228 | my_db | localhost | my_db | Query   | 34862 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'melanotaenia-lacustris' AND  |
| 17229 | my_db | localhost | my_db | Query   | 34861 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'mikrogeophagus-altispinosus' |
| 17230 | my_db | localhost | my_db | Query   | 34861 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.ID = 25503 AND wp_posts.post_type = 'atta |
| 17231 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'piaractus-brachypomus' AND w |
| 17232 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17233 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('knowledge-base') AND (post_type |
| 17234 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17235 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17236 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17237 | my_db | localhost | my_db | Query   | 34803 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17238 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('m','migrate') AND (post_type =  |
| 17239 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'hemichromis-lifalili' AND wp |
| 17240 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17241 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17242 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17243 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17244 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums','lofiversion','index-ph |
| 17245 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17246 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT post_modified_gmt FROM wp_posts WHERE post_status = 'publish' AND post_type IN ('post', 'page |
| 17247 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 17248 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'geophagus-brokopondo' AND wp |
| 17249 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND wp_posts.post_name = 'hyphessobrycon-amandae' AND  |
| 17253 | my_db | localhost | my_db | Query   | 34788 | Waiting for table level lock | SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = 'post' AN |
| 17255 | my_db | localhost | my_db | Query   | 34786 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('knowledge-base') AND (post_type |
| 17260 | my_db | localhost | my_db | Query   | 34786 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('s','silver-sand') AND (post_typ |
| 17262 | my_db | localhost | my_db | Query   | 34786 | Waiting for table level lock | SELECT ID, post_name, post_parent FROM wp_posts WHERE post_name IN ('forums') AND (post_type = 'page |
| 25505 | root      | localhost | NULL      | Query   |     2 | NULL                         | SHOW PROCESSLIST

フラグを付けて実行mysqlしてみました--log-slow-queries[slow-queries]が、何もしていないようですslow-queries。少なくとも、ボックスのどこにも呼び出されたファイルが見つかりません。

これはどこかで疑わしいクエリだと思いますが、どこから調べればよいのかわかりません!

編集：ヒットと設定

  • MySQL は現在、最大 500 の同時接続を実行しています
  • スクリプトでいくつかのパフォーマンス テストを試みていたため、PHP のメモリ制限は非常に高くなっています (約 1Gb)。
  • この Web サイトだけでも (ボックスには他にもあります。現在、すべてがこのエラーの影響を受けています)、週に約 30,000 のユニークな訪問者と 250,000 のヒットがあります。
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2 に答える 2

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高負荷レベルでの私の経験では、ワードプレス（テーブル名に基づいてワードプレスであると想定しています）は、遅いクエリにはかなり悪いです。テーブルが特定のサイズに達すると (ここでは post テーブルが主な問題です)、クエリは非常に遅くなり、ペースを維持するために最適化する必要があります。

MySQL の最適化の用語では、バッファと MySQL のクエリ キャッシュに割り当てられるメモリの量に関係します。ワードプレスの場合、データベースから可能な限りオフロードすることです。

スタックの一番上から一番下まで、さまざまなことができます。

  1. ワードプレスの最適化。未使用のプラグインを削除し、ページ キャッシングを追加し (W3 Total Cache がゴールド スタンダードです)、データベースから可能な限りオフロードします。また、投稿ごとに保存する「リビジョン」の数を減らすことも検討してください (こちらを参照)。5 年前のサイトの場合、投稿よりもはるかに多くのリビジョンがある可能性が高いため、投稿検索が遅くなります (コード スニペットのクエリはすべて投稿検索です)。

  2. MySQL の最適化。これはトリッキーなものです.調整できるダイヤルがたくさんあり、適切なバランスを見つけることは暗い芸術のようなものだからです. そこにはたくさんの記事やチュートリアルがあります。具体的に推奨するものはありませんが、単純なグーグルで my.cnf ファイルにできる調整に関する多くの情報が表示されます。

于 2012-07-10T09:52:52.690 に答える
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これを試して、遅いクエリをキャッチできます。

mysql 構成ファイルである /etc/my.cnf ファイル内

これらの 2 行をセクション [mysqld] の下に置きます。

slow_query_log_file=/var/log/mysql-log-slow-queries.log
long_query_time=2

この助けを願っています。

于 2012-07-10T10:09:17.747 に答える