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Cloudflare Concurrent Connection Limit

Authors
  • avatar
    Name
    Sunway
    Twitter

1 Background

One day, I receive that some services is down, and some users also reports that they can not connect with our services

This services cluster is load balance by Cloudflare LoadBalancing, and I set alert configuration in cloudflare, but I did not receive any alert from cloudflare, that so weird.

so I use this command to do health check for our service:

docker run --rm -it ghcr.io/vi/websocat wss://testnet-rpc.cess.network/ws/

and it just returns a message: 502 bad gateway

2 Reason

So I just ssh to the real host and check the chain service log, and I found all backend services is work fine.

Service log as below: RpcNodeLog

The container log seems that this service works fine, and then, I check the others services, and it also works fine.

I search the cloudflare community for help and finally got it. The reason why the backend services has no problem but still returns 502 is because of the Cloudflare Concurrent Connection Limit

but it still got a little difference, I got 502 err code and the others guys got 503 err code, maybe cloudflare has updated the err code return after 2019.

When I calculated all my services concurrent connection and found that: cloudflare support almost 40000+ concurrent websocket connections for my services for free, that is amazing.

3 Solution

  • Solution1: Restart all backend services and disrupt all connections, make the concurrent websocket connections number re-calculate from zero

  • Solution2: Upgrade domain to Pro edition, according to the community, Pro edition can give roughly a 5x increase over Free edition, and business a similar increase.

Finally, I spend 240$ to upgrade domain to pro edition, and the services restore after 10 min.(maybe we should upgrade to business to get more services)

4 Summary

In the chain mainland, we call Cloudflare as 赛博佛祖 or 赛博义父 because its free services like warp, pages,workers...

I believe most developers behind the great fire wall hope that Cloudflare will get better and better.

Currently, we spend over $1,000 on Cloudflare every year, and it will increase in the future. We are willing to pay for quality services, not just to be a freeloader.

The last earning report caused cloudflare stock price #net to fall a lot ,and I hope this upcoming earnings report will bring good news