How to keep-alive a WebSocket?

[tobyjaguar]

Infura is telling me that I should ping the connection to keep it alive for websockets. They suggested using this options in web3:
https://web3js.readthedocs.io/en/v1.2.11/web3.html#providers

Is there comparable options in ethers that I can take advantage of?

[tobyjaguar]

any traction on this?

[ricmoo]

Sorry, I haven't had a chance to look into this yet, I have a few other admin things I want to get to first.

Is the problem it disconnects after a short time? You may be able to use .on("block", () => { }) to keep the connection alive. I haven't personally had any issue with short-lived connections, but my purposes are generally at least slightly noisy...

[tobyjaguar]

thanks for the response. Do you important stuff, just been going back and forth with infura trying to track down why one service loses connection, and the other doesn't. Both are connecting the same with ethers via websocket. My first attempt at a fix was the above, I too thought that might work. Infura recommends adding a keep-alive ping. I am still not sure what the issue here is, but I was curious if there was a comparable options. thanks

[ricmoo]

My gas-ticker stays connected for hours at a time, but I do use that serve-forever.sh script to make sure it keeps on trucking... Maybe a band-aid solution for now though...

[tobyjaguar]

I will look into this, thank you. And I do need to write some reconciliation script to re-connect if it gets severed. I'll take a look, thanks again.

[rymnc]

@tobyjaguar you can use the web3-providers-ws package and pass it in as a Web3Provider to ethers
the web3-providers-ws package has many options such as reconnect, keep alive,etc
Here

[tobyjaguar]

Interesting. I ended up writing a heartbeat function into my process as there are many reconnects with infura. But this looks promising as a more permanent solution. Would need to resubscribe to events on reconnect. I will look into it. Thank you.

[rymnc]

yeah you can probably submit a pr to the web3-providers-ws package that auto subscribes on reconnect!

[b10c77]

@tobyjaguar can you share your heartbeat function? I'm on the same boat, looking to re-connect ethers.js web socket in case the connection is dropped. Thanks!

[tobyjaguar]

I never explored @rymnc 's suggestion regarding the options of the web3-providers-ws package:

      // Useful to keep a connection alive
      keepalive: true,
      keepaliveInterval: 60000 // ms

That is probably a better way to go, but I had already attempted a heartbeat process. After tinkering with it for a couple weeks this seems to work for my purposes. It is probably a bit overkill, but I grab a beat tolerance from config, register a timestamp and then just continuously consume the heartbeat function().

function updateTimestamp() {
  provider.on("block", async block => {
    lastTimestamp = moment();
    //(lastTimestamp) ? console.log(`time: ${lastTimestamp}`) : null;
  })
}

async function heartbeat() {
  //check if our lastTimestamp is before now minus 10 seconds ago, if after we lost sync
  if (lastTimestamp && (lastTimestamp.isBefore(moment().subtract(((beat/PER_SECOND)+1), 'seconds')))) {
    console.log("lost connection to provider, attempting to reset...");

    // get the latest provider we have saved
    //provider = getProvider();

    // remove all listeners subscribed
    provider.removeAllListeners();

    // we should not have any listeners
    console.log(`listeners: ${provider.listenerCount()}`);

    // destroy connection
    await provider.destroy();

    // reconnection to provider
    setProvider();

    // save provider locally
    provider = getProvider();

    // register all out listeners
    require('./registerEvents')();
    console.log(`listeners: ${provider.listenerCount()}`);

    // update our lastTimestamp
    lastTimestamp = moment();
    console.log(`time: ${lastTimestamp}`);
    updateTimestamp();
  }
  await sleep(beat);
  heartbeat();
}

The above has kept my processes online since I implemented the above. Things go horribly wrong if the process loses the internet connection, but it can heal a lost connection with infura, which seems to happen all the time.

[rymnc]

I think it would be best if someone extended the websocket provider/made a pr on the existing one which handles websocket reconnections + resubscriptions etc!

[tobyjaguar]

alright, my band-aid solution doesn't work so well on L2 as those blocks are inconsistent.
@rymnc with your recommendation of using web3-providers-ws, would I pass the instantiated client to ethers like so:
provider = new ethers.providers.WebSocketProvider(wsProvider);

This is how I am currently connecting to L2, until infura catches up.

[tobyjaguar]

@smartins don't know if you ever got a keepalive function going, but I have had success with this design:
#1053 (comment)

thanks to @mikevercoelen for posting

[Ailein]

@tobyjaguar I also face this kind of problem, Can you post your code