Sequelize.js Sequelize并发事务在PostgreSQL中的事务中变为空闲

当我使用

sequelize.transaction（）

创建足够多的并发事务时，sequelize不会进行

例如，如果我在pool.max=5的情况下启动5个事务，sequelize将执行

启动事务在postgres中，不执行任何进一步的操作

测试用例是：

const { Sequelize } = require('sequelize');

function parseArgs(argv = process.argv) {
  return argv.slice(argv.findIndex((x) => x === __filename) + 1);
}

const args = parseArgs();
const count = parseInt(args[0]) || 5;

const sequelize = new Sequelize('postgres://postgres@localhost:5432/postgres', {
  seederStorage: 'sequelize',
  dialect: 'postgres',
  define: {
    timestamps: false,
  },
  // logging: false,
  pool: {
    max: count, // keeping max pool size to equal to concurrent transactions
  },
});

async function query() {
  await sequelize.transaction(async (transaction) => {
    // Just doing any query inside transaction. Using model yields same result.
    // If no query is run inside transaction, sequelize progresses fine.
    const one = await sequelize.query('SELECT 1');
    console.log('Queried one', one);
  });
}

async function concurrentQuery({ count = 1 }) {
  const promises = [];
  for (let i = 0; i < count; i++) {
    promises.push(query());
  }
  console.log('Started promises', { count: promises.length });
  await Promise.all(promises);
}


concurrentQuery({ count })
  .then(() => {
    console.log('result', 'pool config', sequelize.config.pool);
  })
  .catch((err) => {
    console.error(err);
  })
  .finally(() => {
    sequelize.close()
      .then(() => {
        console.log('Closed sequelize');
      })
      .catch((err) => {
        console.error(err);
      });
  });

和查询postgres：

postgres@localhost:postgres> SELECT  pid,  now() - pg_stat_activity.query_start AS duration,  query,  state FROM pg_stat_activity WHERE (now() - pg_stat_activity.query_start) >
  interval '2 seconds';
+-------+----------------+--------------------+---------------------+
| pid   | duration       | query              | state               |
|-------+----------------+--------------------+---------------------|
| 1042  | 0:00:22.191851 | START TRANSACTION; | idle in transaction |
| 1043  | 0:00:22.187831 | START TRANSACTION; | idle in transaction |
| 1044  | 0:00:22.188163 | START TRANSACTION; | idle in transaction |
| 1045  | 0:00:22.188316 | START TRANSACTION; | idle in transaction |
| 1046  | 0:00:22.180694 | START TRANSACTION; | idle in transaction |
+-------+----------------+--------------------+---------------------+
SELECT 5
Time: 0.019s

使用Sequelize v5（具有节点12）和v6（具有节点14）进行测试

这是虫子吗？或者，我应该提供足够的pool.max来弥补交通堵塞吗？如果预期并发事务的峰值为200，则将pool.max设置为201，可能会导致postgres过载？
数据库事务和池中可用连接的数量与您的问题所示的方式无关。无论您的查询使用的是什么事务，连接池都会工作——它会根据需要将它们移交给您。当您启动事务时，它确保您在事务中所做的更改是原子的，并且不会与来自事务外部的更新冲突。由于您没有将创建的事务传递到后续查询中，它将挂起，等待您提交或回滚事务中的更改。如果使用
async/await
，则更易于阅读

异步函数查询（）{
//获得交易
const transaction=wait sequelize.transaction（）；
//将事务传递给查询
wait one=wait sequelize.query（'SELECT 1'，{transaction}）；
//等待事务。提交（）；
console.log（'查询一个'，一个）；
}
谢谢。我完全忽略了这样一个事实，即我需要传递
事务
对象。通过传递事务，我不会在postgres中出现“事务中空闲”的行为。
postgres@localhost:postgres> SELECT  pid,  now() - pg_stat_activity.query_start AS duration,  query,  state FROM pg_stat_activity WHERE (now() - pg_stat_activity.query_start) >
  interval '2 seconds';
+-------+----------------+--------------------+---------------------+
| pid   | duration       | query              | state               |
|-------+----------------+--------------------+---------------------|
| 1042  | 0:00:22.191851 | START TRANSACTION; | idle in transaction |
| 1043  | 0:00:22.187831 | START TRANSACTION; | idle in transaction |
| 1044  | 0:00:22.188163 | START TRANSACTION; | idle in transaction |
| 1045  | 0:00:22.188316 | START TRANSACTION; | idle in transaction |
| 1046  | 0:00:22.180694 | START TRANSACTION; | idle in transaction |
+-------+----------------+--------------------+---------------------+
SELECT 5
Time: 0.019s