Postgres 被锁定在 Heroku

Question

我只是偶然发现了一个错误，这是我以前从未见过，也从未听说过的。 我刚刚部署了对生产的更新（从登台开始，一切都很好），然后我看到，我收到了来自 postgres 的死锁。 我的 SQL 查询不再通过，API 卡住了

这是一个 ActiveRecord::ConnectionTimeoutError:

could not obtain a connection from the pool within 5.000 seconds (waited 5.000 seconds); all pooled connections were in use

在我搜索了一段时间后，我看到 Heroku 提供了一个简单的常见问题解答，说明 PostgreSQL 何时被锁定并且需要再次释放进程。 所以我去了，检查了流程，这就是我所看到的：

  pid  |        state        |  source   |    username    |   running_for   |       transaction_start       | waiting |                                                                                                                 query
-------+---------------------+-----------+----------------+-----------------+-------------------------------+---------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 24358 | active              | bin/rails | xxx            | 00:00:43.026836 | 2021-02-11 15:53:42.672799+00 | t       | INSERT INTO "users" ("email", "password_digest", "full_name", "guest_user_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id"
 24378 | active              | bin/rails | xxx            | 00:00:44.874495 | 2021-02-11 15:53:40.82514+00  | t       | INSERT INTO "users" ("email", "password_digest", "full_name", "guest_user_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id"
 24348 | active              | bin/rails | xxx            | 00:01:01.145712 | 2021-02-11 15:53:24.553923+00 | t       | INSERT INTO "users" ("email", "password_digest", "full_name", "guest_user_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id"
 24347 | idle in transaction | bin/rails | xxx            | 00:01:08.554992 | 2021-02-11 15:53:17.144643+00 | t       | SELECT "active_storage_attachments".* FROM "active_storage_attachments" WHERE "active_storage_attachments"."record_id" = $1 AND "active_storage_attachments"."record_type" = $2 AND "active_storage_attachments"."name" = $3 LIMIT $4
 24349 | idle in transaction | bin/rails | xxx            | 00:01:34.246178 | 2021-02-11 15:52:51.453457+00 | t       | SELECT "active_storage_attachments".* FROM "active_storage_attachments" WHERE "active_storage_attachments"."record_id" = $1 AND "active_storage_attachments"."record_type" = $2 AND "active_storage_attachments"."name" = $3 LIMIT $4
(5 rows)

在做了应该是最好的解决方案（杀死所有进程并重新运行服务器）之后，它似乎又开始运行了。 但是，当我使用新功能时（谢天谢地，这还没有在应用程序中发布）我再次看到这种奇怪的行为。

我认为这是非常奇怪的行为，因为数据库上的死锁通常只发生在有两个进程更改列而不是SELECTing ...

我可以做些什么来删除它并可以再次自由使用数据库？