Re: [Twisted-Python] Writing a low-level network debugging tool

2015-12-03 Thread Jonathan Ballet
On 11/27/2015 03:39 PM, Phil Mayers wrote: On 27/11/15 14:05, Jonathan Ballet wrote: - how many tries did it require * if there were several tries, the timing of each ones Typically, application-layer code doesn't retry a DNS lookup; rather the c or other runtime will handle this, for

Re: [Twisted-Python] Writing a low-level network debugging tool

2015-11-27 Thread Phil Mayers
On 27/11/15 14:39, Phil Mayers wrote: But the info above may be a helpful start. You may also want to look at TCP_CC_INFO. See the kernel source: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/net/ipv4/tcp.c?id=refs/tags/v4.4-rc2 ...for an idea of what else is availabl

Re: [Twisted-Python] Writing a low-level network debugging tool

2015-11-27 Thread Phil Mayers
On 27/11/15 14:05, Jonathan Ballet wrote: * how long does it take to resolv the domain name to (at least) one of its IP address - against a specified name server or using the system configured servers That is relatively straightforward. - how many tries did it require * if there w

[Twisted-Python] Writing a low-level network debugging tool

2015-11-27 Thread Jonathan Ballet
Hi all, I'm trying to toubleshoot network connectivity issues we have in one of our office and I would like to monitor some metrics which seems to be relevant for us, especially when trying to open TCP connections towards external endpoints. In particular, I'm looking for a way to get the fo