Messages not delivered, only after sending a new message

[janvlug]

• [x ] I have searched open and closed issues for duplicates

Bug description

I sent a few messages to a contact (099.1 in log). I noticed that they were delivered to the server, but not to the recipient (one checkmark).
Nine hours later, the messages were still not delivered to the recipient (still one checkmark). But after that I sent a new message to the same recipient, all the pending messages were directly delivered as well. The recipient confirmed that he received the messages together with the new one (so nine hours late).

Steps to reproduce

I cannot reproduce this.

Actual result:
Messages were not delivered, or only together with sending a new message (which was nine hours later).

Expected result:
Signal keeps trying delivering messages, independent whether new messages are sent or not.

Screenshots

None

Platform info

Linux, Fedora 27, fully up to date, Signal installed via flatpak.

Signal version:
v1.1.0

Operating System:
Linux nyx 4.14.13-300.fc27.x86_64 #1 SMP Thu Jan 11 04:00:01 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Linked device version:
bq Aquaris 3.5, Android 4.2.2

Link to debug log

https://gist.github.com/anonymous/db775d7a7c1b378af0a556ccec1be909

[loxK]

I think it is a bug with Signal mobile app or Signal server. It happens very often to my contact that don't use Signal much. Makes it difficult to convert them to using it :(

[scottnonnenberg]

When you get that single checkmark, it means that the server has accepted the message and it is now ready to be downloaded by your target recipient. Previous reports like this have indicated that it was a problem with the receiving device's internet connection, which was intermittent. Only periodically could it connect and successfully download new messages. Your contact can help verify this by looking at the behavior of other apps on the device. If they submit a Signal debug log from that device, that would help us be sure.

Lastly, you can verify that it isn't the server by sending a message, and then noting how long it takes to show up on your other devices. Send a message on your phone, and then see how long it takes to show up on desktop. Or vice versa. This is a good test because it's a round-trip with the server.

[janvlug]

I asked the recipient to submit a debug log. But the relevant logging is already gone.
The log that was still there is rather short: https://gist.githubusercontent.com/anonymous/20c115d17421dd0691395a7cc5c8e50c/raw/27be97ebc5f4e951d91ceb01f43f6e71e7ecc4fe/cat.log

[scottnonnenberg]

@janvlug Thanks for providing that log. At the very least we know that it's Android 4.14.0. But I do also notice what might be a few indications of network connectivity problems - construction of a connection, then immediate destruction:

01-22 19:36:46.763  9703  9703 D InputTransport: Input channel constructed: fd=113
01-22 19:36:46.763  9703  9703 D InputTransport: Input channel destroyed: fd=68

Let's train your contact to grab a log immediately after this happens next time. :0)

[janvlug]

Maybe some related issues happened. I connected my Android phone to my desktop in order to transfer some files to my desktop computer. In order to do so, the external microsd had to be unmounted in the phone, and I got a warning that some apps might stop functioning (Signal is installed on the SD card).

I forgot to restart my phone after the transfer in order to remount the sdcard, so I suspect that Signal was not functioning.

Then, the next day, I started working on my desktop and saw on Signal Desktop some new messages. I sent a reply, but they only got one checkmark.

Next I rebooted my Android phone and tried to open Signal. Signal crashed a few times before my password was accepted. I did some testing sending messages to myself. One message sent from the desktop to my phone is still not delivered. Also a message to another group still as a single checkmark.

Here are logs from my desktop and my phone:
https://gist.github.com/anonymous/2e398c0a9e659c7928871313cdba7cbc
https://gist.github.com/anonymous/59f18171625219026a4173d85fc55367

[janvlug]

Screenshot of messages that is not delivered to the group, even after successfully sending another message.

[janvlug]

BTW. I'm pretty sure that I also missed some messages that were sent in the group.

[janvlug]

Here is a debug log of the contact that I sent a message to (not in a group). This contact confirms that he received a messages twice, while on my Signal Desktop only one of the messages has the double checkmark.

https://gist.github.com/anonymous/1d037b1786946c7048c34d4e18344c81

[janvlug]

Screenshot of my Signal desktop, while the contact confirmed the both messages were received.

[scottnonnenberg]

One checkmark can frequently happen when your recipient is offline. When they next come online, and they download the message, you'll receive a delivery receipt message, adding that second check. Given the way signals notifications work, it does make sense that sending another message could wake up your recipient's device, causing it to download the new message as well as previous. If you provide logs for that recipient device, we could start tracking down why it wasn't downloading new messages before that last message.

Now, certainly, if a later message has two checks, you would expect that any message above it would have the checks. I can dig into that more if you click into those single-check messages and provide the timestamps shown, as well as your time zone.

Lastly, it looks like your last update only included the Android log, but the desktop log is really what we're looking for since the problems are showing up in desktop. Thanks!

[janvlug]

The log of my Signal desktop is here:
https://gist.github.com/anonymous/2e398c0a9e659c7928871313cdba7cbc
(was also mentioned in an earlier comment, together with the log of my own Android phone from the same time).

I understand that one checkmark happens when the recipient is offline. Would it somehow be possible that clients check based on a time interval whether there are still messages in the queue for them for which no notification has been received? What happens to messages that are never fetched from the server? Will the be purged eventually? This is the log of the recipient device: https://gist.github.com/anonymous/1d037b1786946c7048c34d4e18344c81

By the way, I noticed that the logs on Android devices cover only a small timespan. It happened a few times that the logs of my contacts did not contain the information regarding a problem any more. To be honest, it feels already a bit uncomfortable for me to ask others to submit debug logs for an application that I recommend for them. Urging them to do that immediately because otherwise the log is useful feels rather awkward. Could the log size on Android phones be increased?

Timestamps for the group conversation:

• Message one checkmark: Saturday, January 27, 2018 12:09 PM (all recipients have only one checkmark)
• Message with two checkmarks: Saturday, January 27, 2018 12:29 PM (all recipients have a double checkmark)

Timestamps for the message exchange with one contact [REDACTED]099:

• Message with one checkmark: Saturday, January 27, 2018 10:30 AM
• Message with two checkmarks: Saturday, January 27, 2018 12:38 PM

I'm in the CET timezone, UTC +1.

[scottnonnenberg]

Thanks for that extra detail. One thing to check is to see if the behavior remains through a restart. It's possible that the missing checkmarks you're seeing are purely a visual thing, and will appear properly with a restart.

[janvlug]

Even after a restart they stay single ticks. So it is not a purely visual thing.
BTW, I verified on my phone (Android), the messages that I sent and that have only one tick on the desktop are completely absent on my Android phone.

[ghost]

Hi, I hope I can help. I have this issue on the receiving end. Often, messages from contacts only get delivered when they send another message, and then both are received at the same time. There is no way for me to get to the undelivered message beforehand: I restarted my phone, switched between WiFi and 4G data, and opened up the signal app on my Android 8 phone several times. The message that is 'stuck' only appears with another message that the contact sends afterwards.

Here is a debug log from a few days ago. On 2018-10-22 at 12:27, I sent a message to a contact. The contact responded at 12:46, but I only received this answer together with another message at 17:53.

[scottnonnenberg-signal]

Just to be clear, this is a phone issue. Double check-mark only happens if the phone downloads the message. If you get one checkmark in the message, you've successfully uploaded it to the server.

@davidplotzki Please enter a bug in the Signal Android repository: https://github.com/signalapp/Signal-Android/issues

[EvanHahn-Signal]

This issue has been inactive for over 2 years, so I'm going to close. Let me know if that's wrong and I'll reopen.