The dpdkstat plugin

This plugin is optional and only has a specific use case: monitoring DPDK applications that don't expose stats in any other way than the DPDK xstats API.

Data Plane Development Kit (DPDK) is a set of drivers and libraries for fast packet processing. Please note that this plugin is a polling based plugin rather than an events based plugin (using it will drive up core utilization on a system).

PLEASE DO NOT USE THIS PLUGIN FOR OVS-DPDK. dpdkstat is really for DPDK applications that have no other way of exposing stats. For OVS or OVS-with-DPDK the Open vSwitch plugins available in collectd 5.8.0 should be used for collecting stats and events. In addition the OVS plugin is events based rather than polling based and will have a smaller footprint on the system.

Summary

The dpdkstat plugin has the following requirements:

DPDK 16.04 or later
GCC 4.9 or later

You can also build with GCC 4.8 (e.g. Ubuntu 14.04) if you specify the SSSE3 instruction set manually:

make -j CFLAGS+='-mssse3'

Building DPDK

Setup the build environment:

Ensure that you have GCC 4.9 or later. Ubuntu 14.04, for example, has GCC 4.8 by default and requires an upgrade:
```
add-apt-repository ppa:ubuntu-toolchain-r/test
apt-get update
apt-get install gcc-4.9
```
If you know that the platform that you wish to run collectd on supports the SSSE3 instruction set, GCC 4.8 also works if you enable SSSE3 manually:
```
make -j CFLAGS+='-mssse3'
```
Clone DPDK:
```
git clone git://dpdk.org/dpdk
```
Checkout the DPDK system requirements and make sure you have the required tools and hugepage setup as specified there.

Note: It's recommended to use the 1GB hugepage setup for best performance, please follow the instruction for "Reserving Hugepages for DPDK Use" in the link above.

However if you plan on configuring 2MB hugepages on the fly please ensure to add appropriate commands to reserve hugepages in a system startup script if collectd is booted at system startup time. These commands include:
```
mkdir -p /mnt/huge
mount -t hugetlbfs nodev /mnt/huge
echo 64 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
```

To configure the DPDK build for the combined shared library and enable autoload of pmd drivers modify config/common_base in your DPDK as follows

#
# Compile to share library
#
-CONFIG_RTE_BUILD_SHARED_LIB=n
+CONFIG_RTE_BUILD_SHARED_LIB=y

# Default driver path (or "" to disable)
-CONFIG_RTE_EAL_PMD_PATH=""
+CONFIG_RTE_EAL_PMD_PATH="/usr/lib/dpdk-pmd/"

Prepare the configuration for the appropriate target as specified at: http://dpdk.org/doc/guides/linux_gsg/build_dpdk.html.

For example:
```
make config T=x86_64-native-linuxapp-gcc
```
Build the target:
```
make
```
Install DPDK to /usr
```
sudo make install prefix=/usr
```
Create dpdk-pmd folder
```
mkdir -p /usr/lib/dpdk-pmd
```
Create symlinks to pmd drivers
```
find /usr/lib -type f -name 'librte_pmd*' | while read path ; do ln -s $path /usr/lib/dpdk-pmd/`echo $path | grep -o 'librte_.*so'` ;  done
```
Note 1: You must run make install as the configuration of collectd with DPDK expects DPDK to be installed somewhere.

Note 2: If you don't specify a prefix then DPDK will be installed in /usr/local/.

Note 3: If you are not root then use sudo to make install DPDK to the appropriate location.

Note 4: You MUST create symlink to a NIC driver lib. This way collectd will be able to work with device bound to dpdk.
Check that the DPDK library has been installed in /usr/lib or /lib:
```
ls /usr/lib | grep dpdk
```
Bind the interfaces to use with dpdkstat to DPDK:

DPDK devices can be setup with either the VFIO (for DPDK 1.7+) or UIO modules.

Note: UIO requires inserting an out of tree driver igb_uio.ko that is available in DPDK.

UIO Setup:
- Insert uio.ko:
```
sudo modprobe uio
```
- Insert igb_uio.ko:
```
sudo insmod $DPDK_BUILD/kmod/igb_uio.ko
```
- Bind network device to igb_uio:
```
sudo $DPDK_DIR/tools/dpdk_nic_bind.py --bind=igb_uio eth1
```
VFIO Setup:
- VFIO needs to be supported in the kernel and the BIOS. More information can be found at: http://dpdk.org/doc/guides/linux_gsg/build_dpdk.html.
- Insert the vfio-pci.ko module:
```
modprobe vfio-pci
```
- Set the correct permissions for the VFIO device:
```
sudo /usr/bin/chmod a+x /dev/vfio
sudo /usr/bin/chmod 0666 /dev/vfio/*
```
- Bind the network device to vfio-pci:
```
sudo $DPDK_DIR/tools/dpdk_nic_bind.py --bind=vfio-pci eth1
```
  Note: Please ensure to add appropriate commands to bind the network interfaces to DPDK in a system startup script if collectd is booted at system startup time.
- Run ldconfig to update the shared library cache.

Build collectd with DPDK

Note: DPDK 16.04 is the minimum version and currently supported version of DPDK required for the dpdkstat plugin. This is to allow the plugin to take advantage of functions added to detect if the DPDK primary process is alive.

Note: The Address-Space Layout Randomization (ASLR) security feature in Linux should be disabled, in order for the same hugepage memory mappings to be present in all DPDK multi-process applications. Note that this has security implications.

To disable ASLR:

echo 0 > /proc/sys/kernel/randomize_va_space

To fully enable ASLR:

echo 2 > /proc/sys/kernel/randomize_va_space

Generate the build script as specified below. (i.e. run build.sh).
Configure collectd with the DPDK shared library. If DPDK is installed in custom installation path you can specify headers include path using LIBDPDK_CPPFLAGS variable and libraries path with LIBDPDK_LDFLAGS. Example:
```
./configure

or for custom DPKD installation:

./configure LIBDPDK_CPPFLAGS="-I/home/joe/include/dpdk" LIBDPDK_LDFLAGS="-L/home/joe/usr/lib"
```
Make sure that libdpdk and dpdkstat are enabled in the configure output.

Expected output:
```
Libraries:
...
libdpdk  . . . . . . . . yes

Modules:
...
dpdkstat . . . . . . .yes
```
Build collectd:

make -j && make -j install

Note: As mentioned above, if you are building on Ubuntu 14.04 with GCC <= 4.8.X, you need to use:
```
make -j CFLAGS+='-mssse3' && make -j install
```

Caveats

The same PCI device configuration should be passed to the primary process as the secondary process uses the same port indexes as the primary.
A blocklist / allowlist of NICs isn't supported yet.
Plugin initialization time depends on read interval. It requires 5 read cycles to set up internal buffers and states. During that time no statistics are submitted.
If number of DPDK ports is increased while plugin is running, internal buffers are resized. That requires 3 read cycles and no port statistics are submitted in that time.

7.4 KiB Raw Permalink Blame History

The dpdkstat plugin

Summary

Building DPDK

Build collectd with DPDK

Caveats

License

7.4 KiB

Raw Permalink Blame History