JSON construction error: buffer size exceeded

JSON construction error: buffer size exceeded

[marko]

Hello.

I am looking into monitor with sudo stap --monitor -o result.log
my4.stap meetmaker, but I get these errors:

WARNING: JSON construction error: buffer size exceeded, consider .maxsize(2325).
WARNING: JSON construction error: buffer size exceeded, consider .maxsize(2336).
WARNING: JSON construction error: buffer size exceeded, consider .maxsize(2337).

I've read about maxsize in man stap and tried to increase limits with

sudo stap -D MAXSTRINGLEN=5000 --monitor -o result.log my4.stap meetmaker

and with

sudo stap -D STP_PROCFS_BUFSIZE=5000 --monitor -o result.log my4.stap meetmaker

but still get these errors.

$ stap --version
Systemtap translator/driver (version 3.0/0.166/0.165, rpm 3.0-2.fc23)
Copyright (C) 2005-2015 Red Hat, Inc. and others
This is free software; see the source for copying conditions.
enabled features: AVAHI BOOST_SHARED_PTR BOOST_STRING_REF DYNINST JAVA
LIBRPM LIBSQLITE3 LIBVIRT LIBXML2 NLS NSS TR1_UNORDERED_MAP READLINE

$ uname -a
Linux fedora 4.5.6-200.fc23.x86_64 #1 SMP Wed Jun 1 21:28:20 UTC 2016
x86_64 x86_64 x86_64 GNU/Linux

Thanks!

Re: JSON construction error: buffer size exceeded

[Felix Lu]

Hi Marko,

Monitor mode is still undergoing development so there may be some bugs.

> I am looking into monitor with sudo stap --monitor -o result.log
> my4.stap meetmaker, but I get these errors:
> 
> WARNING: JSON construction error: buffer size exceeded, consider
> .maxsize(2325).
> WARNING: JSON construction error: buffer size exceeded, consider
> .maxsize(2336).
> WARNING: JSON construction error: buffer size exceeded, consider
> .maxsize(2337).
> 

This is an error related to the internal implementation of monitor mode.

The upstream version is now much more stable if you would like to try that.

It would be much appreciated if you could provide your script to help
diagnose if this error still exists.

Thanks,

Felix

Re: JSON construction error: buffer size exceeded

[marko]

On Thu, Jun 16, 2016 at 4:43 PM, Felix Lu <flu@redhat.com> wrote:
> The upstream version is now much more stable if you would like to try that.

I will try upstream version. Thank you.

> It would be much appreciated if you could provide your script to help
> diagnose if this error still exists.

I am using systemtap to probe user space program. So without the
program it would not be useful I think.
Anyway, it's here
https://gist.github.com/mkevac/5fa180bf49ccb05855a2d555655bcd8d

Re: JSON construction error: buffer size exceeded

[marko]

On Thu, Jun 16, 2016 at 4:55 PM, marko@kevac.org <marko@kevac.org> wrote:
> I will try upstream version. Thank you.

It works on latest master from git.