Intermittent "Client is offline" rejection from Realtime Database `get()`

[XuluWarrior]

[REQUIRED] Describe your environment

• Operating System version: AWS Lambda - node-14
• Firebase SDK version: 9.1.1
• Firebase Product: database

[REQUIRED] Describe the problem

Since updating my code to use Firebase 9.x and the new modular API, I am getting intermittent "Client is offline" promise rejections when calling get().
There is a Firebase Google Group that has other users that have experienced the same problem but I can't find a related issue in GitHub, so I thought I would raise one.

I currently running 9.1.1 and so will try upgrading to 9.1.2. I will also enable logging.

Steps to reproduce:

Relevant Code:

initializeApp(config)
database = await getDatabase();
selectionsRef = ref(database, path);
await get(child(selectionsRef, systemName), "value");

Call stack:

Error: Error: Client is offline.
  File "/var/task/node_modules/@firebase/database/dist/index.node.cjs.js", line 11517, col 31, in null.<anonymous>
    return Promise.reject(new Error(err));

[jbalidiong]

Hi @XuluWarrior, thanks for reaching out. I tried replicating, but I wasn't able to reproduce the error. If I can replicate the issue, I can have a better look into it. Please share a minimal, but complete sample of a project that I can run locally.

[XuluWarrior]

Hi @jbalidiong

I don't have consistent reproduction case as I haven't actually seen it running on my local machine. In my case I think it's related to the code being run as a lambda and hence can be frozen and restored in between calls. I can see in my logs that Firebase is often disconnecting and reconnecting but usually it successfully reconnects and there is no error.

Here are the logs before and after the error this morning. Perversely the last log before the error is "Primary connection is healthy" ;)

loggly_disconnections.txt

[schmidt-sebastian]

@IanWyszynski Can you take a look?

[qlereboursBS]

I have the same issue.
I was not able to reproduce it on my local machine, but it's reproducible on a distant environment:

• I'm authenticating to the website, which redirects me to a page loading my user data
• The error doesn't show when loading data
• I can refresh as many times as I want, the error won't show
• If I wait a few minutes or a few hours, when refreshing the page, the error is showing

You can reproduce on the dev environment of my website: dev.traveledmap.com
Since I was able to reproduce it only when logged for the moment, I think you would have to create an account.

[qlereboursBS]

I was just able to reproduce it on my local machine after waiting for a few minutes to refresh the page. However I had the error just once, and then the data successfully loaded (which was not the case on the screen I sent)

[qlereboursBS]

I was able to have kind of a reproduction on a new project, but I think that it's the expected behavior:

• I'm putting a breakpoint in the ready_ method
• I refresh the page that will load some data (get(ref(getDatabase(), 'my-ref'))
• I'm waiting for a few seconds, and the release the breakpoint
• I can see the error in the console.
  I'm not sure if it's the expected behavior because the database request is done just after I release the breakpoint and however the request fails

Maybe it could be related to our issue?

Kazam_screencast_00002.mp4

[qlereboursBS]

I was able to have the issue with my simple example, without breakpoints:

• clone this repository: https://github.com/qlereboursBS/firebase-client-offline-reproduction
• replace the two "TODOs" in the code with your firebase config, and the path to the data you want to fetch
• run yarn && yarn dev to start the project
• Go to localhost:3000 and Hard refresh (ctrl + maj + R on Chrome) the page approximately 10 times, the error should appear randomly (I faced it approximately every 6 times)

@jbalidiong @schmidt-sebastian can you have a look please?
To my mind, this is a high priority bug since it should impact all projects using realtime database

[jbalidiong]

Hi @qlereboursBS, thanks for adding information regarding this issue. I just want to confirm if the repository you've provided contains any code with Firebase? Currently, I'm seeing the default files when created with Next.js. Maybe some files are not uploaded in the repository.

[qlereboursBS]

I'm really sorry, I just realized that the commit and push didn't work, I just pushed it.
You will find the code in pages/_app.js