mtcp

README

mTCP is a highly scalable user-level TCP stack for multicore systems. mTCP source code is distributed under the Modified BSD License. For more detail, please refer to the LICENSE. The license term of io_engine driver and ported applications may differ from the mTCP’s.

Prerequisites

We require the following libraries to run mTCP.

• libdpdk (Intel’s DPDK package*) or libps (PacketShader I/O engine library) or netmap driver
• libnuma
• libpthread
• librt
• libgmp (for DPDK/ONVM driver)

Compling PSIO/DPDK/NETMAP/ONVM driver requires kernel headers.

• For Debian/Ubuntu, try apt-get install linux-headers-$(uname -r)

We have modified the dpdk package to export net_device stat data (for Intel-based Ethernet adapters only) to the OS. To achieve this, we have created a new LKM dpdk-iface-kmow. We also modified mk/rte.app.mk file to ease the compilation process of mTCP applications. We recommend using our package for DPDK installation.

Included directories

mtcp: mtcp source code directory

• mtcp/src: source code
• mtcp/src/include: mTCP’s internal header files
• mtcp/lib: library file
• mtcp/include: header files that applications will use

io_engine: event-driven packet I/O engine (io_engine)

• io_engine/driver - driver source code
• io_engine/lib - io_engine library
• io_engine/include - io_engine header files
• io_engine/samples - sample io_engine applications (not mTCP’s)

dpdk - Intel’s Data Plane Development Kit

• dpdk/…

apps: mTCP applications

• apps/example - example applications (see README)
• apps/lighttpd-1.4.32 - mTCP-ported lighttpd (see INSTALL)
• apps/apache_benchmark - mTCP-ported apache benchmark (ab) (see README-mtcp)

util: useful source code for applications

config: sample mTCP configuration files (may not be necessary)

Install guides

mTCP can be prepared in four ways.

DPDK VERSION

1. Download DPDK submodule.

   git submodule init
   git submodule update
   

2. Setup DPDK.

   ./setup_mtcp_dpdk_env.sh [<path to $RTE_SDK>]
   

   • Press [15] to compile x86_64-native-linuxapp-gcc version
   • Press [17] to install igb_uio driver for Intel NICs
   • Press [21] to setup 2048 2MB hugepages
   • Press [23] to register the Ethernet ports

   • Press [34] to quit the tool

   • Only those devices will work with DPDK drivers that are listed on this page: http://dpdk.org/doc/nics. Please make sure that your NIC is compatible before moving on to the next step.

   • We use dpdk/ submodule as our DPDK driver. FYI, you can pass a different dpdk source directory as command line argument.

3. Bring the dpdk compatible interfaces up, and then set RTE_SDK and RTE_TARGET environment variables. If you are using Intel NICs, the interfaces will have dpdk prefix.

   sudo ifconfig dpdk0 x.x.x.x netmask 255.255.255.0 up
   export RTE_SDK=`echo $PWD`/dpdk
   export RTE_TARGET=x86_64-native-linuxapp-gcc
   

4. Setup mtcp library:

   ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET
   make
   

   • By default, mTCP assumes that there are 16 CPUs in your system. You can set the CPU limit, e.g. on a 32-core system, by using the following command:

     ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET CFLAGS="-DMAX_CPUS=32"
     

     Please note that your NIC should support RSS queues equal to the MAX_CPUS value (since mTCP expects a one-to-one RSS queue to CPU binding).

   • In case ./configure script prints an error, run the following command; and then re-do step-4 (configure again):

     autoreconf -ivf
     

   • checksum offloading in the NIC is now ENABLED (by default)!!!

     • this only works for dpdk at the moment
     • use ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET --disable-hwcsum to disable checksum offloading.

   • check libmtcp.a in mtcp/lib

   • check header files in mtcp/include

   • check example binary files in apps/example

5. Check the configurations in apps/example

   • epserver.conf for server-side configuration
   • epwget.conf for client-side configuration
   • you may write your own configuration file for your application

6. Run the applications!

7. You can revert back all your changes by running the following script.

   ./setup_linux_env.sh [<path to $RTE_SDK>]
   

   • Press [29] to unbind the Ethernet ports
   • Press [30] to remove igb_uio.ko driver
   • Press [33] to remove hugepage mappings
   • Press [34] to quit the tool

PSIO VERSION

1. make in io_engine/driver:

   make
   

   • check ps_ixgbe.ko
   • please note that psio only runs on linux-2.6.x kernels (linux-2.6.32 ~ linux-2.6.38)

2. install the driver:

   ./install.py <# cores> <# cores>

- refer to http://shader.kaist.edu/packetshader/io_engine/
- you may need to change the ip address in install.py:46

1. Setup mtcp library:

   ./configure --with-psio-lib=<$path_to_ioengine>
   # e.g. ./configure --with-psio-lib=`echo $PWD`/io_engine
   make
   

   • By default, mTCP assumes that there are 16 CPUs in your system. You can set the CPU limit, e.g. on a 8-core system, by using the following command:

     ./configure --with-psio-lib=`echo $PWD`/io_engine CFLAGS="-DMAX_CPUS=8"
     

   Please note that your NIC should support RSS queues equal to the MAX_CPUS value (since mTCP expects a one-to-one RSS queue to CPU binding).

   • In case ./configure script prints an error, run the following command; and then re-do step-3 (configure again):

     autoreconf -ivf
     

   • check libmtcp.a in mtcp/lib

   • check header files in mtcp/include

   • check example binary files in apps/example

2. Check the configurations in apps/example

   • epserver.conf for server-side configuration
   • epwget.conf for client-side configuration
   • you may write your own configuration file for your application

3. Run the applications!

ONVM VERSION

NEW: Now you can run mTCP applications (server + client) locally. A local setup is useful when only 1 machine is available for the experiment. ONVM configurations are placed as .conf files in apps/example directory. ONVM basics are explained in https://github.com/sdnfv/openNetVM.

Before running the applications make sure that onvm_mgr is running.
Also, no core overlap between applications and onvm_mgr is allowed.

1. Install openNetVM following these instructions

2. Set up the dpdk interfaces:

   ./setup_mtcp_onvm_env.sh
   

3. Next bring the dpdk-registered interfaces up. This can be setup using:

   sudo ifconfig dpdk0 x.x.x.x netmask 255.255.255.0 up
   

4. Setup mtcp library

   ./configure --with-dpdk-lib=$<path_to_dpdk> --with-onvm-lib=$<path_to_onvm_lib>
   # e.g. ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET --with-onvm-lib=`echo $ONVM_HOME`/onvm
   make
   

   • By default, mTCP assumes that there are 16 CPUs in your system. You can set the CPU limit, e.g. on a 32-core system, by using the following command:

     ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET --with-onvm-lib=$<path_to_onvm_lib> CFLAGS="-DMAX_CPUS=32"
     

   Please note that your NIC should support RSS queues equal to the MAX_CPUS value (since mTCP expects a one-to-one RSS queue to CPU binding).

   • In case ./configure script prints an error, run the following command; and then re-do step-4 (configure again):

     autoreconf -ivf
     

   • checksum offloading in the NIC is now ENABLED (by default)!!!

   • this only works for dpdk at the moment

   • use ./configure --with-dpdk-lib=$RTE_SDK/$RTE_TARGET --with-onvm-lib=$<path_to_onvm_lib> --disable-hwcsum to disable checksum offloading.

   • check libmtcp.a in mtcp/lib

   • check header files in mtcp/include

   • check example binary files in apps/example

5. Check the configurations in apps/example

   • epserver.conf for server-side configuration
   • epwget.conf for client-side configuration
   • you may write your own configuration file for your application

6. Run the applications!

7. You can revert back all your changes by running the following script.

   ./setup_linux_env.sh
   

   • Press [29] to unbind the Ethernet ports
   • Press [30] to remove igb_uio.ko driver
   • Press [33] to remove hugepage mappings
   • Press [34] to quit the tool

Notes

Once you have started onvm_mgr, sometimes an mTCP application may fail to get launched due to an error resembling the one mentioned below:

• EAL: FATAL: Cannot init memory
• Cannot mmap memory for rte_config at [0x7ffff7fb6000], got [0x7ffff7e74000] - please use '--base-virtaddr' option
• EAL: Cannot mmap device resource file /sys/bus/pci/devices/0000:06:00.0/resource3 to address: 0x7ffff7ff1000

To prevent this, use the base virtual address parameter to run the ONVM manager, e.g.:

cd openNetVM/onvm  
./go.sh 1,2,3 1 -s stdout -a 0x7f000000000 

NETMAP VERSION

See README.netmap for details.

Tested environments

mTCP runs on Linux-based operating systems (2.6.x for PSIO) with generic x86_64 CPUs, but to help evaluation, we provide our tested environments as follows.

Intel Xeon E5-2690 octacore CPU @ 2.90 GHz 32 GB of RAM (4 memory channels)
10 GbE NIC with Intel 82599 chipset (specifically Intel X520-DA2)
Debian 6.0.7 (Linux 2.6.32-5-amd64)

Intel Core i7-3770 quadcore CPU @ 3.40 GHz 16 GB of RAM (2 memory channels)
10 GbE NIC with Intel 82599 chipset (specifically Intel X520-DA2)
Ubuntu 10.04 (Linux 2.6.32-47)

Event-driven PacketShader I/O engine (extended io_engine-0.2)

• PSIO is currently only compatible with Linux-2.6.

We tested the DPDK version (polling driver) with Linux-3.13.0 kernel.

Notes

1. mTCP currently runs with fixed memory pools. That means, the size of TCP receive and send buffers are fixed at the startup and does not increase dynamically. This could be performance limit to the large long-lived connections. Be sure to configure the buffer size appropriately to your size of workload.

2. The client side of mTCP supports mtcp_init_rss() to create an address pool that can be used to fetch available address space in O(1). To easily congest the server side, this function should be called at the application startup.

3. The supported socket options are limited for right now. Please refer to the mtcp/src/api.c for more detail.

4. The counterpart of mTCP should enable TCP timestamp.

5. mTCP has been tested with the following Ethernet adapters:

   1. Intel-82598 ixgbe (Max-queue-limit: 16)
   2. Intel-82599 ixgbe (Max-queue-limit: 16)
   3. Intel-I350 igb (Max-queue-limit: 08)
   4. Intel-X710 i40e (Max-queue-limit: ~)
   5. Intel-X722 i40e (Max-queue-limit: ~)

Frequently asked questions

1. How can I quit the application?

   • Use ^C to gracefully shutdown the application. Two consecutive ^C (separated by 1 sec) will force quit.

2. My application doesn’t use the address specified from ifconfig.

   • For some Linux distros(e.g. Ubuntu), NetworkManager may re-assign a different IP address, or delete the assigned IP address.

   • Disable NetworkManager temporarily if that’s the case. NetworkManager will be re-enabled upon reboot.

   sudo service network-manager stop
   

3. Can I statically set the routing or arp table?

   • Yes, mTCP allows static route and arp configuration. Go to the config directory and see sample_route.conf or sample_arp.conf. Copy and adapt it to your condition and link (ln -s) the config directory to the application directory. mTCP will find config/route.conf and config/arp.conf for static configuration.

Caution

1. Do not remove I/O driver (ps_ixgbe/igb_uio) while running mTCP applications. The application will panic!

2. Use the ps_ixgbe/dpdk driver contained in this package, not the one from some other place (e.g., from io_engine github).

Contacts

GitHub issue board is the preferred way to report bugs and ask questions about mTCP.

CONTACTS FOR THE AUTHORS

User mailing list <mtcp-user at list.ndsl.kaist.edu>
EunYoung Jeong <notav at ndsl.kaist.edu>
M. Asim Jamshed <ajamshed at ndsl.kaist.edu>