Installing BCC to Use eBPF Tracing Tools

Before You Begin

You need the following:

1. A system running on a Linux distribution and a Linux kernel version 4.1 or later. Review the Getting Started guide if you do not yet have a compatible system. For more information, review the Getting Started guide.

2. Login credentials to the system for either the root user (not recommended) or a standard user account (belonging to the sudo group) and the ability to access the system through SSH or Lish. Review the Securing Your Server guide for assistance on creating and securing a standard user account.

Note

Some commands in this guide require elevated privileges and are prefixed with the sudo command. If you are logged in as the root use (not recommended), you can omit the sudo prefix if desired. If you’re not familiar with the sudo command, see the Linux Users and Groups guide.

What is eBPF?

Berkeley Packet Filter (BPF) is an execution engine subsystem in the kernel that processes a virtual instruction set. BPF has been extended recently as eBPF for providing a safe way to extend kernel functionality. BPF is now used for software defined networking, observability, security enforcement, and more. The main front-ends for BPF performance tools are BPF Compiler Collection (BCC) and bpftrace.

eBPF tracing is used for:

• any ext4 operations that take longer than 50 ms
• run queue latency, as a histogram
• packets and applications that are experiencing TCP retransmits.
• the stack trace when threads block (off-CPU), and how long they block
• security modules and software defined networks.

Install BCC on different distributions of Linode using packages

Ubuntu 18.04 or later

The stable and the nightly packages are built for Ubuntu Bionic (18.04).

Stable and Signed Packages

Install BCC using stable packages by adding the appropriate key and repository to Advanced Package Tools (APT) by typing the following commands:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4052245BD4284CDD
echo "deb https://repo.iovisor.org/apt/$(lsb_release -cs) $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/iovisor.list
sudo apt-get update
sudo apt-get install bcc-tools libbcc-examples linux-headers-$(uname -r)

Tools are installed under /usr/share/bcc/tools.

Nightly Packages

Install BCC using nightly packages by typing the following commands:

echo "deb [trusted=yes] https://repo.iovisor.org/apt/bionic bionic-nightly main" | sudo tee /etc/apt/sources.list.d/iovisor.list
sudo apt-get update
sudo apt-get install bcc-tools libbcc-examples linux-headers-$(uname -r)

The tools are installed under /usr/share/bcc/tools.

Ubuntu Packages

BCC is also available from the standard Ubuntu multiverse repository, under the package name bpfcc-tools:

sudo apt-get install bpfcc-tools linux-headers-$(uname -r)

The tools are installed in /sbin with a -bpfcc extension. To verify the installation run sudo opensnoop-bpfcc.

Debian 10

Debian Packages

BCC and its tools are available in the standard Debian main repository. From the source package bpfcc under the package names bpfcc-tools, python-bpfcc, libbpfcc, and libbpfcc-dev.

sudo apt-get install bpfcc-tools linux-headers-$(uname -r)

The tools are installed in /sbin with a -bpfcc extension. Try running sudo opensnoop-bpfcc.

Fedora 32 or later

As of Fedora 30, bcc binaries are available in the standard repository.

sudo dnf install bcc

Note

If you keep getting Failed to load program: Operation not permitted when you run the hello_world.py example as root, then you need to lift the kernel lockdown. For more information, see FAQ.

Gentoo - Portage

Install BCC using the following command:

sudo emerge dev-util/bcc

Use the command sudo ACCEPT_KEYWORDS="~amd64" emerge dev-util/bcc if there is a message that reads similar to:

!!! All ebuilds that could satisfy "dev-util/bcc" have been masked.
!!! One of the following masked packages is required to complete your request:
- dev-util/bcc-0.20.0-r1::gentoo (masked by: ~amd64 keyword)
- dev-util/bcc-0.19.0-r1::gentoo (masked by: ~amd64 keyword

The appropriate dependencies are pulled automatically.

Alpine 3.11 or later

As of Alpine 3.11, bcc binaries are available in the community repository:

sudo apk add bcc-tools bcc-doc

The tools are installed in /usr/share/bcc/tools.

Python Compatibility

The binary packages include bindings for Python 3 only. The Python-based tools assume that a python binary is available at /usr/bin/python, but that may not be true on recent versions of Alpine. If you encounter errors like <tool-name>: not found, you can try creating a symlink to the Python 3.x binary:

sudo ln -s $(which python3) /usr/bin/python

Containers

Alpine Linux is often used as a base system for containers. BCC can be used in such an environment by launching the container in privileged mode with kernel modules available through bind mounts:

sudo docker run --rm -it --privileged \
  -v /lib/modules:/lib/modules:ro \
  -v /sys:/sys:ro \
  -v /usr/src:/usr/src:ro \
  alpine:3.12

CentOS - Source

For CentOS 7.6 only

1. Install build dependencies:

   sudo yum install -y epel-release
     sudo yum update -y
     sudo yum groupinstall -y "Development tools"
     sudo yum install -y elfutils-libelf-devel cmake3 git bison flex ncurses-devel
     sudo yum install -y luajit luajit-devel  # for Lua support

2. Install and compile LLVM from source code:

   curl  -LO  http://releases.llvm.org/7.0.1/llvm-7.0.1.src.tar.xz
     curl  -LO  http://releases.llvm.org/7.0.1/cfe-7.0.1.src.tar.xz
     tar -xf cfe-7.0.1.src.tar.xz
     tar -xf llvm-7.0.1.src.tar.xz
   
     mkdir clang-build
     mkdir llvm-build
   
     cd llvm-build
     cmake3 -G "Unix Makefiles" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
     -DCMAKE_BUILD_TYPE=Release ../llvm-7.0.1.src
     make
     sudo make install
   
     cd ../clang-build
     cmake3 -G "Unix Makefiles" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
     -DCMAKE_BUILD_TYPE=Release ../cfe-7.0.1.src
     make
     sudo make install
     cd ..

3. Optional: Install from centos-release-scl:

   yum install -y centos-release-scl
     yum-config-manager --enable rhel-server-rhscl-7-rpms
     yum install -y devtoolset-7 llvm-toolset-7 llvm-toolset-7-llvm-devel llvm-toolset-7-llvm-static llvm-toolset-7-clang-devel
     source scl_source enable devtoolset-7 llvm-toolset-7

   For permanently enabling scl environment, see: https://access.redhat.com/solutions/527703.

4. Install and compile BCC:

   git clone https://github.com/iovisor/bcc.git
     mkdir bcc/build; cd bcc/build
     cmake3 ..
     make
     sudo make install

Useful commands using the BCC (eBPF) tools:

• Trace new processes: execsnoop
• Trace file opens with process and filename: opensnoop
• Summarize block I/O (disk) latency as a power-of-2 distribution by disk: biolatency -D
• Summarize block I/O size as a power-of-2 distribution by program name: bitesize
• Trace common ext4 file system operations slower than 1 millisecond: ext4slower 1
• Trace TCP active connections (connect()) with IP address and ports: tcpconnect
• Trace TCP passive connections (accept()) with IP address and ports: tcpaccept
• Trace TCP connections to local port 80, with session duration: tcplife -L 80
• Trace TCP retransmissions with IP addresses and TCP state: tcpretrans
• Sample stack traces at 49 Hertz for 10 seconds, emit folded format (for flame graphs): profile -fd -F 49 10
• Trace details and latency of resolver DNS lookups: gethostlatency
• Trace commands issued in all running bash shells: bashreadline

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• iovisor