When tailing log messages or extracting a file, or viewing a file and large amounts of text scrolls across the screen, the SSH terminal session hangs

Hello,

Thank you for reaching out to us regarding this,

I see, could you confirm which type of data source you are using with RDM?

That being said, I'm also wondering if there is any error message or perhaps logs of this under "Help" -> "Application Logs" generated when the issue occurs?

Are you encountering this issue with all your SSH Shell entries?

Let me know,

Best regards,

Hi benpatridge,

I opened a ticket to investigate these problematic behaviour.
which type of data source are you using and does the issues occurs with all your ssh entries ?

Best regards,

Yes it occurs on any SSH Terminal.
I am unable to gather the logs because it hangs.

I am going to try to duplicate it again and will post more information.

Hi, I faced a similar situation and can say a little bit more:


After running tail -f /var/log/* I get first several lines of logs and then there are 2 variants of the issue:

1) Whole RDM just hangs and I cannot do anything within the interface. The only way out is to force quit the application and start it again.
I use default settings for SSH connections except font and colours. However, the issue appears also on full default settings.

2) Only the active session hangs and I need to close the tab with the connection and start a new session.
As I noticed, this happens when logging is enabled. If I disable the logging the first sceenario happens.



RDM version 2024.1.8.6 on MacOS Sonoma 14.4.1

Hi,

Thanks for the logs and information !
We have reviewed them and we think we may have a clue as to what the problem is. It looks like the terminal is attempting to start a ZMODEM transfer and that is failing. Apparently, ZMODEM transfers are started when the output in the terminal contains one of ZMODEM's escape sequence ( something like **B00 ). When the output reaches that, it thinks the next part will be a file transfer, but it's not so it causes an error. Please try doing the steps that you described as causing the hang with a log file containing only normal letters and let us know if that works. If it does, consider sanitizing your logs so that they won't contain escape sequences.

We will look into a way to improve this in the future, but for now hopefully this will fix your issue.

Best regards,

Hi,

It seems that the problem is really in the escape characters.

To reproduce the issue with a normalized text I did the following:

1) collected normalized syslog files with

zcat syslog.*.gz >> BIGLOG.txt

several times (like 20 or so)
and got a .txt file that is over 700 MB

2) tried to look inside the file with
cat BIGLOG.txt

and the terminal worked fine.

Please could you tell whether it is possible to disable starting ZMODEM transfer or ignore its escape sequence in a normal SSH session by any settings in RDM?

Thanks for the logs and information !
We have reviewed them and we think we may have a clue as to what the problem is. It looks like the terminal is attempting to start a ZMODEM transfer and that is failing. Apparently, ZMODEM transfers are started when the output in the terminal contains one of ZMODEM's escape sequence ( something like **B00 ). When the output reaches that, it thinks the next part will be a file transfer, but it's not so it causes an error. Please try doing the steps that you described as causing the hang with a log file containing only normal letters and let us know if that works. If it does, consider sanitizing your logs so that they won't contain escape sequences.

We will look into a way to improve this in the future, but for now hopefully this will fix your issue.

Best regards,

Hi,

I'm glad to hear we found the problem. Unfortunately, there is no setting in RDM to ignore the escape sequence. The only thing you can do is to remove them from your log before displaying them. After looking a bit more into it, it looks like I was wrong about the escape sequence I previously stated. It looks like the escape is done by a character of value 24 ( Cancel character ). If you can sanitize your logs and remove all the chars with that value, it should display correctly.

We will look into adding a setting to ignore them, but until then, hopefully removing the escape character can fix this issue.

Best regards,

Yeah. If this comes back I will let you know. I haven't duplicated it lately. So you can close this issue for now.