订阅不稳定。 Prisma因GqlConnectionTerminate错误终止

Question

我刚刚在我的API中实现了使用graphql-yoga的订阅。我有一台棱镜服务器，其配置如下：

databases:
  default:
    connector: postgres
    host: 
    database: prisma
    port: 5432
    user: admin
    password: ${DB_PASSWORD}
    migrations: true
    rawAccess: true
    ssl: true
    connectionLimit: 5

请注意，由于我要连接到允许连接数有限的Google Cloud SQL实例，因此我限制了连接数。现在，我有4个Yoga应用程序连接到这台棱镜服务器。问题是，有时订阅工作正常，有时会引发以下错误（在操场上）：

{
  "error": "Could not connect to websocket endpoint wss://yourapi.com/subscriptions. Please check if the endpoint url is correct."
}

当我检查prisma容器日志时，发现了这一点：

Deployment worker initialization complete.
Version is up to date.
[SubscriptionSessionActor] Received unknown message: com.prisma.subscriptions.protocol.SubscriptionProtocolV07$Requests$GqlConnectionTerminate$@494aa66a
Killed
Obtaining exclusive agent lock...
Initializing workers...
Obtaining exclusive agent lock... Successful.
Successfully started 1 workers.
Server running on :4466

我的API在Nginx代理后面：

server {
  server_name example.com;
  listen 443 ssl http2;

  location / {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-NginX-Proxy true;
    proxy_set_header X-Custom-Referrer "idToken";
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_max_temp_file_size 0;
    proxy_pass http://127.0.0.1:4050;
    proxy_redirect off;
    proxy_read_timeout 240s;
  }


    ssl_certificate ___ # managed by Certbot
    ssl_certificate_key ___ # managed by Certbot
}

我不知道问题出在哪里。任何线索或指导将不胜感激。预先感谢。