Sending messages is slow in large groups

[xAbdaziz]

When I send a message in a group with 100+ members it takes 5-10 seconds to send, meanwhile in small groups & PM it's sent instantly.
I'm using the example code in godocs.

I also noticed that there's warnings spam in my console when I send a message
[Client WARN] Failed to fetch prekey for 123456789.0:15@s.whatsapp.net: invalid prekey in prekey response: prekey node doesn't contain ID tag

Can someone please tell me what should I do to fix this issue?

[mamur-rezeki]

Also looking for the solution.

[mamur-rezeki]

So I've migrate to postgresql database (SSD). Simple text message could take ± 4 seconds with 266 group participants. It is similar with SQLite database on SSD storage, take ± 6 seconds for same message and group. While SQLite on HDD is pretty slow for ± 55 seconds.

Three scenarios have tested on initial message send and secondary message if in this case they have prekey caching (or not).

I don't know if then Message node encryption is using databases to store the prekey or Identity and get it for encrypting 1 message node for every number participants. I'm running on 150Mbps network speed.

[rull05]

any solution?

[SoursopID]

Encrypting a message for a large group is very slow. So we need to avoid it being encrypted by whatsmeow .
The current solution is limiting the participants in this list

whatsmeow/send.go

Lines 539 to 542 in 350073d

	participants, err = cli.getGroupMembers(ctx, to)
	if err != nil {
	return "", nil, fmt.Errorf("failed to get group members: %w", err)
	}

just like this :

participants = []types.JID{ownID}

[SoursopID]

So, as far as I know, when a message is sent to a group chat, by default WhatsMeow will fetch all group participants and then retrieve all participant devices known to our WhatsMeow client based on the participant list.

For example, if there are 100 participants and each participant has 3 devices that have interacted in the group, then:

100 * 3 = 300 devices (300 keys)

Thus, one chat message we send will be created and encrypted with each different key (300 keys).

The encryption process takes a lot of time due to several factors, such as bottlenecks in the speed of getting/storing keys (R/W) with the database used.

Actually, all the process estimates can be seen on whatsmeow.SendResponse.

What I did here is replace the participant list with a list that only contains the client's own JID (ownJID) (send.go#sendGroup()).

Therefore, the message will only be encrypted for our own devices.

Next, I thought that participants might request again to our client to fetch the message we sent earlier. Then the client will resend the message with the requester’s key.

Now, during the re-sending process, because the request process may be very fast and numerous, calculated based on active participants in the group chat, for example, 60 participants.

If the R/W database is overwhelmed by the goroutine process and causes "Database Locked," then some keys might not be stored and also not available when the client tries to resend the message with unavailable keys.

This is where the "Segmentation error nil" appears because libsignal does not check if the key is available or not.

Some users might encounter this message description:

"Waiting for this message"

[PBatista]

I made the changes and actually, the sending process was really quick... I'm only worried about the keys and shipping issues... in this case, is it possible to continue doing this sending process and then in the backgroud or something like that? , did he try to get these keys that he tried to send? And another, an exclamation symbol always appears in the messages talking about the WhatsApp version, that doesn't influence it, right? And thank you in advance for your help and answers, it’s helping a lot! Thanks

[a5r0n]

Encrypting a message for a large group is very slow. So we need to avoid it being encrypted by whatsmeow .
The current solution is limiting the participants in this list

whatsmeow/send.go

Lines 539 to 542 in 350073d

	participants, err = cli.getGroupMembers(ctx, to)
	if err != nil {
	return "", nil, fmt.Errorf("failed to get group members: %w", err)
	}

just like this :

participants = []types.JID{ownID}

I'm not sure if that is a safe solution, you probably just make it easier for WhatsApp to detect and ban..

[SoursopID]

Encrypting a message for a large group is very slow. So we need to avoid it being encrypted by whatsmeow .
The current solution is limiting the participants in this list

whatsmeow/send.go

Lines 539 to 542 in 350073d

	participants, err = cli.getGroupMembers(ctx, to)
	if err != nil {
	return "", nil, fmt.Errorf("failed to get group members: %w", err)
	}

just like this :

participants = []types.JID{ownID}

I'm not sure if that is a safe solution, you probably just make it easier for WhatsApp to detect and ban..

Please let us know if you have a better solution.

[PBatista]

@JustSoursop Regarding the issue of trying to forward messages to other devices, did you have anything in mind or was it just an idea to be implemented? I wanted to see if it would be possible to do this in the background or something like that.