netutils-linux 0.4.1

Bunch of utils to simplify linux network troubleshooting and performance tuning.

netutils-linux
======

.. image:: https://travis-ci.org/strizhechenko/netutils-linux.svg?branch=master
:target: https://travis-ci.org/strizhechenko/netutils-linux

It's just a bunch of utils to simplify Linux network troubleshooting and performance tuning, developed in order to help `Carbon Reductor`_ techsupport and later automate the whole linux performance tuning process out of box.

.. _Carbon Reductor: http://www.carbonsoft.ru/products/carbon-reductor-5/
Project state
======
Beta. Few script were gathered together, shortly documented, one has some tests and packed into python package.

Some were cleaned up, some - not. Most of them were being written in bash, not python, maybe they'll be ported later.

In next few weeks, it will receive something like a 'tuned' with autodetection of best settings for all the system feature.

Installation
======
.. code :: shell

pip install netutils-linux

Utils
======

irqtop
------
- Show you a rate of interrupts
- based on /proc/interrupts file
- Hides the interrupts with small rate to show a better picture.

Example output:

.. code::

Total: 1398 1539
CPU0 CPU1
22: 233 227 IO-APIC-fasteoi eth1
28: 91 98 PCI-MSI-edge eth0
LOC: 1021 1035 Local timer interrupts
CAL: 48 172 Function call interrupts


softirq-net-rx-top
------
- Show you a rate of receiving packets
- Based on /proc/softirqs
- Sometimes shows much more CPUs than really exists

Example output:

.. code::

11.22, 11.20, 7.90
1 2897
2 2552
3 0
4 0

11.29, 11.21, 7.93
1 2182
2 2814
3 0
4 0

missed-pkts-monitor
------
- Detects when were packets missed (maybe it will give some idea of correlation with something)
- Easy to use in tactical, not strategic debug, without deployment of graphite/influxdb
- Based on `ip -s -s link` output

link-rx-rate
------
- Shows how many packets/bytes network interface receives
- Based on /proc/net/dev

Example output:

.. code::

0 mbit/s 1576 pps
0 mbit/s 1085 pps
0 mbit/s 390 pps
0 mbit/s 673 pps

rss-ladder
------
Automatically set `smp_affinity_list` for IRQ of NIC rx/tx queues for ixgbe/igb/vmxnet3 drivers (they usually work on CPU0 out of the box).

Based on lscpu's output.

It also supports double/quad ladder in case of multiprocessor systems (but you better explicitly specify queue count == core per socket as NIC's driver's param).

.. code::

# rss-ladder eth1 0
- Распределение прерываний eth1 (-TxRx-) на сокете 0
- eth1: irq 67 eth1-TxRx-0 -> 0
- eth1: irq 68 eth1-TxRx-1 -> 1
- eth1: irq 69 eth1-TxRx-2 -> 2
- eth1: irq 70 eth1-TxRx-3 -> 3
- eth1: irq 71 eth1-TxRx-4 -> 8
- eth1: irq 72 eth1-TxRx-5 -> 9
- eth1: irq 73 eth1-TxRx-6 -> 10
- eth1: irq 74 eth1-TxRx-7 -> 11

autorps
------
Enables RPS of NIC on all available CPUs. It may be good for small servers with cheap network cards or a bunch of VLAN.

Later, there will be a support for enabling RPS only for a subgroup of CPUs based on L3 caches.

maximize-cpu-freq
------
Sets every CPU scaling governor mode to performance and set max scaling value for min scaling value. So you will be able to use all power of your processor (useful for latency sensible systems).

rx-buffers-increase
------
rx-buffers-increase utils, that finds and sets compromise-value between avoiding dropped/missing pkts and keeping a latency low.

Example output:

.. code::

# ethtool -g eth1

Ring parameters for eth1:
Pre-set maximums:
RX: 4096
RX Mini: 0
RX Jumbo: 0
TX: 4096
Current hardware settings:
RX: 256
RX Mini: 0
RX Jumbo: 0
TX: 256

# rx-buffers-increase eth1

run: ethtool -G eth1 rx 2048

# rx-buffers-increase eth1

eth1's rx ring buffer already has fine size.

# ethtool -g eth1

Ring parameters for eth1:
Pre-set maximums:
RX: 4096
RX Mini: 0
RX Jumbo: 0
TX: 4096
Current hardware settings:
RX: 2048
RX Mini: 0
RX Jumbo: 0
TX: 256