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Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine developed by the OISF and the Suricata community.


Suricata

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Introduction

Suricata is a network IDS, IPS and NSM engine developed by the OISF and the Suricata community.

Resources

Contributing

We're happily taking patches and other contributions. Please see our Contribution Process for how to get started.

Suricata is a complex piece of software dealing with mostly untrusted input. Mishandling this input will have serious consequences:

  • in IPS mode a crash may knock a network offline
  • in passive mode a compromise of the IDS may lead to loss of critical and confidential data
  • missed detection may lead to undetected compromise of the network

In other words, we think the stakes are pretty high, especially since in many common cases the IDS/IPS will be directly reachable by an attacker.

For this reason, we have developed a QA process that is quite extensive. A consequence is that contributing to Suricata can be a somewhat lengthy process.

On a high level, the steps are:

  1. GitHub-CI based checks. This runs automatically when a pull request is made.
  2. Review by devs from the team and community
  3. QA runs from private QA setups. These are private due to the nature of the test traffic.

Overview of Suricata's QA steps

OISF team members are able to submit builds to our private QA setup. It will run a series of build tests and a regression suite to confirm no existing features break.

The final QA runs takes a few hours minimally, and generally runs overnight. It currently runs:

  • extensive build tests on different OS', compilers, optimization levels, configure features
  • static code analysis using cppcheck, scan-build
  • runtime code analysis using valgrind, AddressSanitizer, LeakSanitizer
  • regression tests for past bugs
  • output validation of logging
  • unix socket testing
  • pcap based fuzz testing using ASAN and LSAN
  • traffic replay based IDS and IPS tests

Next to these tests, based on the type of code change further tests can be run manually:

  • traffic replay testing (multi-gigabit)
  • large pcap collection processing (multi-terabytes)
  • fuzz testing (might take multiple days or even weeks)
  • pcap based performance testing
  • live performance testing
  • various other manual tests based on evaluation of the proposed changes

It's important to realize that almost all of the tests above are used as acceptance tests. If something fails, it's up to you to address this in your code.

One step of the QA is currently run post-merge. We submit builds to the Coverity Scan program. Due to limitations of this (free) service, we can submit once a day max. Of course it can happen that after the merge the community will find issues. For both cases we request you to help address the issues as they may come up.

FAQ

Q: Will you accept my PR?

A: That depends on a number of things, including the code quality. With new features it also depends on whether the team and/or the community think the feature is useful, how much it affects other code and features, the risk of performance regressions, etc.

Q: When will my PR be merged?

A: It depends, if it's a major feature or considered a high risk change, it will probably go into the next major version.

Q: Why was my PR closed?

A: As documented in the Suricata GitHub workflow, we expect a new pull request for every change.

Normally, the team (or community) will give feedback on a pull request after which it is expected to be replaced by an improved PR. So look at the comments. If you disagree with the comments we can still discuss them in the closed PR.

If the PR was closed without comments it's likely due to QA failure. If the GitHub-CI checks failed, the PR should be fixed right away. No need for a discussion about it, unless you believe the QA failure is incorrect.

Q: The compiler/code analyser/tool is wrong, what now?

A: To assist in the automation of the QA, we're not accepting warnings or errors to stay. In some cases this could mean that we add a suppression if the tool supports that (e.g. valgrind, DrMemory). Some warnings can be disabled. In some exceptional cases the only 'solution' is to refactor the code to work around a static code checker limitation false positive. While frustrating, we prefer this over leaving warnings in the output. Warnings tend to get ignored and then increase risk of hiding other warnings.

Q: I think your QA test is wrong

A: If you really think it is, we can discuss how to improve it. But don't come to this conclusion too quickly, more often it's the code that turns out to be wrong.

Q: Do you require signing of a contributor license agreement?

A: Yes, we do this to keep the ownership of Suricata in one hand: the Open Information Security Foundation. See http://suricata.io/about/open-source/ and http://suricata.io/about/contribution-agreement/

Redis is an in-memory database that persists on disk. The data model is key-value, but many different kind of values are supported: Strings, Lists, Sets, Sorted Sets, Hashes, Streams, HyperLogLogs, Bitmaps.


This README is just a fast quick start document. You can find more detailed documentation at redis.io.

What is Redis?

Redis is often referred to as a data structures server. What this means is that Redis provides access to mutable data structures via a set of commands, which are sent using a server-client model with TCP sockets and a simple protocol. So different processes can query and modify the same data structures in a shared way.

Data structures implemented into Redis have a few special properties:

  • Redis cares to store them on disk, even if they are always served and modified into the server memory. This means that Redis is fast, but that it is also non-volatile.
  • The implementation of data structures emphasizes memory efficiency, so data structures inside Redis will likely use less memory compared to the same data structure modelled using a high-level programming language.
  • Redis offers a number of features that are natural to find in a database, like replication, tunable levels of durability, clustering, and high availability.

Another good example is to think of Redis as a more complex version of memcached, where the operations are not just SETs and GETs, but operations that work with complex data types like Lists, Sets, ordered data structures, and so forth.

If you want to know more, this is a list of selected starting points:

Building Redis

Redis can be compiled and used on Linux, OSX, OpenBSD, NetBSD, FreeBSD. We support big endian and little endian architectures, and both 32 bit and 64 bit systems.

It may compile on Solaris derived systems (for instance SmartOS) but our support for this platform is best effort and Redis is not guaranteed to work as well as in Linux, OSX, and *BSD.

It is as simple as:

% make

To build with TLS support, you'll need OpenSSL development libraries (e.g. libssl-dev on Debian/Ubuntu) and run:

% make BUILD_TLS=yes

To build with systemd support, you'll need systemd development libraries (such as libsystemd-dev on Debian/Ubuntu or systemd-devel on CentOS) and run:

% make USE_SYSTEMD=yes

To append a suffix to Redis program names, use:

% make PROG_SUFFIX="-alt"

You can build a 32 bit Redis binary using:

% make 32bit

After building Redis, it is a good idea to test it using:

% make test

If TLS is built, running the tests with TLS enabled (you will need tcl-tls installed):

% ./utils/gen-test-certs.sh% ./runtest --tls

Fixing build problems with dependencies or cached build options

Redis has some dependencies which are included in the deps directory. make does not automatically rebuild dependencies even if something in the source code of dependencies changes.

When you update the source code with git pull or when code inside the dependencies tree is modified in any other way, make sure to use the following command in order to really clean everything and rebuild from scratch:

% make distclean

This will clean: jemalloc, lua, hiredis, linenoise and other dependencies.

Also if you force certain build options like 32bit target, no C compiler optimizations (for debugging purposes), and other similar build time options, those options are cached indefinitely until you issue a make distclean command.

Fixing problems building 32 bit binaries

If after building Redis with a 32 bit target you need to rebuild it with a 64 bit target, or the other way around, you need to perform a make distclean in the root directory of the Redis distribution.

In case of build errors when trying to build a 32 bit binary of Redis, try the following steps:

  • Install the package libc6-dev-i386 (also try g++-multilib).
  • Try using the following command line instead of make 32bit: make CFLAGS="-m32 -march=native" LDFLAGS="-m32"

Allocator

Selecting a non-default memory allocator when building Redis is done by setting the MALLOC environment variable. Redis is compiled and linked against libc malloc by default, with the exception of jemalloc being the default on Linux systems. This default was picked because jemalloc has proven to have fewer fragmentation problems than libc malloc.

To force compiling against libc malloc, use:

% make MALLOC=libc

To compile against jemalloc on Mac OS X systems, use:

% make MALLOC=jemalloc

Monotonic clock

By default, Redis will build using the POSIX clock_gettime function as the monotonic clock source. On most modern systems, the internal processor clock can be used to improve performance. Cautions can be found here: http://oliveryang.net/2015/09/pitfalls-of-TSC-usage/

To build with support for the processor's internal instruction clock, use:

% make CFLAGS="-DUSE_PROCESSOR_CLOCK"

Verbose build

Redis will build with a user-friendly colorized output by default. If you want to see a more verbose output, use the following:

% make V=1

Running Redis

To run Redis with the default configuration, just type:

% cd src% ./redis-server

If you want to provide your redis.conf, you have to run it using an additional parameter (the path of the configuration file):

% cd src% ./redis-server /path/to/redis.conf

It is possible to alter the Redis configuration by passing parameters directly as options using the command line. Examples:

% ./redis-server --port 9999 --replicaof 127.0.0.1 6379% ./redis-server /etc/redis/6379.conf --loglevel debug

All the options in redis.conf are also supported as options using the command line, with exactly the same name.

Running Redis with TLS:

Please consult the TLS.md file for more information on how to use Redis with TLS.

Playing with Redis

You can use redis-cli to play with Redis. Start a redis-server instance, then in another terminal try the following:

% cd src% ./redis-cliredis> pingPONGredis> set foo barOKredis> get foo"bar"redis> incr mycounter(integer) 1redis> incr mycounter(integer) 2redis>

You can find the list of all the available commands at https://redis.io/commands.

Installing Redis

In order to install Redis binaries into /usr/local/bin, just use:

% make install

You can use make PREFIX=/some/other/directory install if you wish to use a different destination.

make install will just install binaries in your system, but will not configure init scripts and configuration files in the appropriate place. This is not needed if you just want to play a bit with Redis, but if you are installing it the proper way for a production system, we have a script that does this for Ubuntu and Debian systems:

% cd utils% ./install_server.sh

Note: install_server.sh will not work on Mac OSX; it is built for Linux only.

The script will ask you a few questions and will setup everything you need to run Redis properly as a background daemon that will start again on system reboots.

You'll be able to stop and start Redis using the script named /etc/init.d/redis_<portnumber>, for instance /etc/init.d/redis_6379.

Code contributions

By contributing code to the Redis project in any form, including sending a pull request via GitHub, a code fragment or patch via private email or public discussion groups, you agree to release your code under the terms of the Redis Software Grant and Contributor License Agreement. Redis software contains contributions to the original Redis core project, which are owned by their contributors and licensed under the 3BSD license. Any copy of that license in this repository applies only to those contributions. Redis releases all Redis project versions from 7.4.x and thereafter under the RSALv2/SSPL dual-license as described in the LICENSE.txt file included in the Redis source distribution.

Please see the CONTRIBUTING.md file in this source distribution for more information. For security bugs and vulnerabilities, please see SECURITY.md.

Redis Trademarks

The purpose of a trademark is to identify the goods and services of a person or company without causing confusion. As the registered owner of its name and logo, Redis accepts certain limited uses of its trademarks but it has requirements that must be followed as described in its Trademark Guidelines available at: https://redis.com/legal/trademark-guidelines/.

Redis internals

If you are reading this README you are likely in front of a Github page or you just untarred the Redis distribution tar ball. In both the cases you are basically one step away from the source code, so here we explain the Redis source code layout, what is in each file as a general idea, the most important functions and structures inside the Redis server and so forth. We keep all the discussion at a high level without digging into the details since this document would be huge otherwise and our code base changes continuously, but a general idea should be a good starting point to understand more. Moreover most of the code is heavily commented and easy to follow.

Source code layout

The Redis root directory just contains this README, the Makefile which calls the real Makefile inside the src directory and an example configuration for Redis and Sentinel. You can find a few shell scripts that are used in order to execute the Redis, Redis Cluster and Redis Sentinel unit tests, which are implemented inside the tests directory.

Inside the root are the following important directories:

  • src: contains the Redis implementation, written in C.
  • tests: contains the unit tests, implemented in Tcl.
  • deps: contains libraries Redis uses. Everything needed to compile Redis is inside this directory; your system just needs to provide libc, a POSIX compatible interface and a C compiler. Notably deps contains a copy of jemalloc, which is the default allocator of Redis under Linux. Note that under deps there are also things which started with the Redis project, but for which the main repository is not redis/redis.

There are a few more directories but they are not very important for our goals here. We'll focus mostly on src, where the Redis implementation is contained, exploring what there is inside each file. The order in which files are exposed is the logical one to follow in order to disclose different layers of complexity incrementally.

Note: lately Redis was refactored quite a bit. Function names and file names have been changed, so you may find that this documentation reflects the unstable branch more closely. For instance, in Redis 3.0 the server.c and server.h files were named redis.c and redis.h. However the overall structure is the same. Keep in mind that all the new developments and pull requests should be performed against the unstable branch.

server.h

The simplest way to understand how a program works is to understand the data structures it uses. So we'll start from the main header file of Redis, which is server.h.

All the server configuration and in general all the shared state is defined in a global structure called server, of type struct redisServer. A few important fields in this structure are:

  • server.db is an array of Redis databases, where data is stored.
  • server.commands is the command table.
  • server.clients is a linked list of clients connected to the server.
  • server.master is a special client, the master, if the instance is a replica.

There are tons of other fields. Most fields are commented directly inside the structure definition.

Another important Redis data structure is the one defining a client. In the past it was called redisClient, now just client. The structure has many fields, here we'll just show the main ones:

struct client { int fd; sds querybuf; int argc; robj **argv; redisDb *db; int flags; list *reply; // ... many other fields ... char buf[PROTO_REPLY_CHUNK_BYTES];}

The client structure defines a connected client:

  • The fd field is the client socket file descriptor.
  • argc and argv are populated with the command the client is executing, so that functions implementing a given Redis command can read the arguments.
  • querybuf accumulates the requests from the client, which are parsed by the Redis server according to the Redis protocol and executed by calling the implementations of the commands the client is executing.
  • reply and buf are dynamic and static buffers that accumulate the replies the server sends to the client. These buffers are incrementally written to the socket as soon as the file descriptor is writable.

As you can see in the client structure above, arguments in a command are described as robj structures. The following is the full robj structure, which defines a Redis object:

struct redisObject { unsigned type:4; unsigned encoding:4; unsigned lru:LRU_BITS; /* LRU time (relative to global lru_clock) or * LFU data (least significant 8 bits frequency * and most significant 16 bits access time). */ int refcount; void *ptr;};

Basically this structure can represent all the basic Redis data types like strings, lists, sets, sorted sets and so forth. The interesting thing is that it has a type field, so that it is possible to know what type a given object has, and a refcount, so that the same object can be referenced in multiple places without allocating it multiple times. Finally the ptr field points to the actual representation of the object, which might vary even for the same type, depending on the encoding used.

Redis objects are used extensively in the Redis internals, however in order to avoid the overhead of indirect accesses, recently in many places we just use plain dynamic strings not wrapped inside a Redis object.

server.c

This is the entry point of the Redis server, where the main() function is defined. The following are the most important steps in order to startup the Redis server.

  • initServerConfig() sets up the default values of the server structure.
  • initServer() allocates the data structures needed to operate, setup the listening socket, and so forth.
  • aeMain() starts the event loop which listens for new connections.

There are two special functions called periodically by the event loop:

  1. serverCron() is called periodically (according to server.hz frequency), and performs tasks that must be performed from time to time, like checking for timed out clients.
  2. beforeSleep() is called every time the event loop fired, Redis served a few requests, and is returning back into the event loop.

Inside server.c you can find code that handles other vital things of the Redis server:

  • call() is used in order to call a given command in the context of a given client.
  • activeExpireCycle() handles eviction of keys with a time to live set via the EXPIRE command.
  • performEvictions() is called when a new write command should be performed but Redis is out of memory according to the maxmemory directive.
  • The global variable redisCommandTable defines all the Redis commands, specifying the name of the command, the function implementing the command, the number of arguments required, and other properties of each command.

commands.c

This file is auto generated by utils/generate-command-code.py, the content is based on the JSON files in the src/commands folder. These are meant to be the single source of truth about the Redis commands, and all the metadata about them. These JSON files are not meant to be used by anyone directly, instead that metadata can be obtained via the COMMAND command.

networking.c

This file defines all the I/O functions with clients, masters and replicas (which in Redis are just special clients):

  • createClient() allocates and initializes a new client.
  • The addReply*() family of functions are used by command implementations in order to append data to the client structure, that will be transmitted to the client as a reply for a given command executed.
  • writeToClient() transmits the data pending in the output buffers to the client and is called by the writable event handlersendReplyToClient().
  • readQueryFromClient() is the readable event handler and accumulates data read from the client into the query buffer.
  • processInputBuffer() is the entry point in order to parse the client query buffer according to the Redis protocol. Once commands are ready to be processed, it calls processCommand() which is defined inside server.c in order to actually execute the command.
  • freeClient() deallocates, disconnects and removes a client.

aof.c and rdb.c

As you can guess from the names, these files implement the RDB and AOF persistence for Redis. Redis uses a persistence model based on the fork() system call in order to create a process with the same (shared) memory content of the main Redis process. This secondary process dumps the content of the memory on disk. This is used by rdb.c to create the snapshots on disk and by aof.c in order to perform the AOF rewrite when the append only file gets too big.

The implementation inside aof.c has additional functions in order to implement an API that allows commands to append new commands into the AOF file as clients execute them.

The call() function defined inside server.c is responsible for calling the functions that in turn will write the commands into the AOF.

db.c

Certain Redis commands operate on specific data types; others are general. Examples of generic commands are DEL and EXPIRE. They operate on keys and not on their values specifically. All those generic commands are defined inside db.c.

Moreover db.c implements an API in order to perform certain operations on the Redis dataset without directly accessing the internal data structures.

The most important functions inside db.c which are used in many command implementations are the following:

  • lookupKeyRead() and lookupKeyWrite() are used in order to get a pointer to the value associated to a given key, or NULL if the key does not exist.
  • dbAdd() and its higher level counterpart setKey() create a new key in a Redis database.
  • dbDelete() removes a key and its associated value.
  • emptyData() removes an entire single database or all the databases defined.

The rest of the file implements the generic commands exposed to the client.

object.c

The robj structure defining Redis objects was already described. Inside object.c there are all the functions that operate with Redis objects at a basic level, like functions to allocate new objects, handle the reference counting and so forth. Notable functions inside this file:

  • incrRefCount() and decrRefCount() are used in order to increment or decrement an object reference count. When it drops to 0 the object is finally freed.
  • createObject() allocates a new object. There are also specialized functions to allocate string objects having a specific content, like createStringObjectFromLongLong() and similar functions.

This file also implements the OBJECT command.

replication.c

This is one of the most complex files inside Redis, it is recommended to approach it only after getting a bit familiar with the rest of the code base. In this file there is the implementation of both the master and replica role of Redis.

One of the most important functions inside this file is replicationFeedSlaves() that writes commands to the clients representing replica instances connected to our master, so that the replicas can get the writes performed by the clients: this way their data set will remain synchronized with the one in the master.

This file also implements both the SYNC and PSYNC commands that are used in order to perform the first synchronization between masters and replicas, or to continue the replication after a disconnection.

Script

The script unit is composed of 3 units:

  • script.c - integration of scripts with Redis (commands execution, set replication/resp, ...)
  • script_lua.c - responsible to execute Lua code, uses script.c to interact with Redis from within the Lua code.
  • function_lua.c - contains the Lua engine implementation, uses script_lua.c to execute the Lua code.
  • functions.c - contains Redis Functions implementation (FUNCTION command), uses functions_lua.c if the function it wants to invoke needs the Lua engine.
  • eval.c - contains the eval implementation using script_lua.c to invoke the Lua code.

Other C files

  • t_hash.c, t_list.c, t_set.c, t_string.c, t_zset.c and t_stream.c contains the implementation of the Redis data types. They implement both an API to access a given data type, and the client command implementations for these data types.
  • ae.c implements the Redis event loop, it's a self contained library which is simple to read and understand.
  • sds.c is the Redis string library, check https://github.com/antirez/sds for more information.
  • anet.c is a library to use POSIX networking in a simpler way compared to the raw interface exposed by the kernel.
  • dict.c is an implementation of a non-blocking hash table which rehashes incrementally.
  • cluster.c implements the Redis Cluster. Probably a good read only after being very familiar with the rest of the Redis code base. If you want to read cluster.c make sure to read the Redis Cluster specification.

Anatomy of a Redis command

All the Redis commands are defined in the following way:

void foobarCommand(client *c) { printf("%s",c->argv[1]->ptr); /* Do something with the argument. */ addReply(c,shared.ok); /* Reply something to the client. */}

The command function is referenced by a JSON file, together with its metadata, see commands.c described above for details. The command flags are documented in the comment above the struct redisCommand in server.h. For other details, please refer to the COMMAND command. https://redis.io/commands/command/

After the command operates in some way, it returns a reply to the client, usually using addReply() or a similar function defined inside networking.c.

There are tons of command implementations inside the Redis source code that can serve as examples of actual commands implementations (e.g. pingCommand). Writing a few toy commands can be a good exercise to get familiar with the code base.

There are also many other files not described here, but it is useless to cover everything. We just want to help you with the first steps. Eventually you'll find your way inside the Redis code base :-)

Enjoy!

Storage Performance Development Kit


Storage Performance Development Kit

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NOTE: The SPDK mailing list has moved to a new location. Please visit this URL to subscribe at the new location. Subscribers from the old location will not be automatically migrated to the new location.

The Storage Performance Development Kit (SPDK) provides a set of tools and libraries for writing high performance, scalable, user-mode storage applications. It achieves high performance by moving all of the necessary drivers into userspace and operating in a polled mode instead of relying on interrupts, which avoids kernel context switches and eliminates interrupt handling overhead.

The development kit currently includes:

In this readme

Documentation

Doxygen API documentation is available, as well as a Porting Guide for porting SPDK to different frameworks and operating systems.

Source Code

git clone https://github.com/spdk/spdkcd spdkgit submodule update --init

Prerequisites

The dependencies can be installed automatically by scripts/pkgdep.sh. The scripts/pkgdep.sh script will automatically install the bare minimum dependencies required to build SPDK. Use --help to see information on installing dependencies for optional components

./scripts/pkgdep.sh

Build

Linux:

./configuremake

FreeBSD: Note: Make sure you have the matching kernel source in /usr/src/ and also note that CONFIG_COVERAGE option is not available right now for FreeBSD builds.

./configuregmake

Unit Tests

./test/unit/unittest.sh

You will see several error messages when running the unit tests, but they are part of the test suite. The final message at the end of the script indicates success or failure.

Vagrant

A Vagrant setup is also provided to create a Linux VM with a virtual NVMe controller to get up and running quickly. Currently this has been tested on MacOS, Ubuntu 16.04.2 LTS and Ubuntu 18.04.3 LTS with the VirtualBox and Libvirt provider. The VirtualBox Extension Pack or [Vagrant Libvirt] (https://github.com/vagrant-libvirt/vagrant-libvirt) must also be installed in order to get the required NVMe support.

Details on the Vagrant setup can be found in the SPDK Vagrant documentation.

AWS

The following setup is known to work on AWS: Image: Ubuntu 18.04 Before running setup.sh, run modprobe vfio-pci then: DRIVER_OVERRIDE=vfio-pci ./setup.sh

Advanced Build Options

Optional components and other build-time configuration are controlled by settings in the Makefile configuration file in the root of the repository. CONFIG contains the base settings for the configure script. This script generates a new file, mk/config.mk, that contains final build settings. For advanced configuration, there are a number of additional options to configure that may be used, or mk/config.mk can simply be created and edited by hand. A description of all possible options is located in CONFIG.

Boolean (on/off) options are configured with a 'y' (yes) or 'n' (no). For example, this line of CONFIG controls whether the optional RDMA (libibverbs) support is enabled:

CONFIG_RDMA?=n

To enable RDMA, this line may be added to mk/config.mk with a 'y' instead of 'n'. For the majority of options this can be done using the configure script. For example:

./configure --with-rdma

Additionally, CONFIG options may also be overridden on the make command line:

make CONFIG_RDMA=y

Users may wish to use a version of DPDK different from the submodule included in the SPDK repository. Note, this includes the ability to build not only from DPDK sources, but also just with the includes and libraries installed via the dpdk and dpdk-devel packages. To specify an alternate DPDK installation, run configure with the --with-dpdk option. For example:

Linux:

./configure --with-dpdk=/path/to/dpdk/x86_64-native-linuxapp-gccmake

FreeBSD:

./configure --with-dpdk=/path/to/dpdk/x86_64-native-bsdapp-clanggmake

The options specified on the make command line take precedence over the values in mk/config.mk. This can be useful if you, for example, generate a mk/config.mk using the configure script and then have one or two options (i.e. debug builds) that you wish to turn on and off frequently.

Shared libraries

By default, the build of the SPDK yields static libraries against which the SPDK applications and examples are linked. Configure option --with-shared provides the ability to produce SPDK shared libraries, in addition to the default static ones. Use of this flag also results in the SPDK executables linked to the shared versions of libraries. SPDK shared libraries by default, are located in ./build/lib. This includes the single SPDK shared lib encompassing all of the SPDK static libs (libspdk.so) as well as individual SPDK shared libs corresponding to each of the SPDK static ones.

In order to start a SPDK app linked with SPDK shared libraries, make sure to do the following steps:

  • run ldconfig specifying the directory containing SPDK shared libraries
  • provide proper LD_LIBRARY_PATH

If DPDK shared libraries are used, you may also need to add DPDK shared libraries to LD_LIBRARY_PATH

Linux:

./configure --with-sharedmakeldconfig -v -n ./build/libLD_LIBRARY_PATH=./build/lib/:./dpdk/build/lib/ ./build/bin/spdk_tgt

Hugepages and Device Binding

Before running an SPDK application, some hugepages must be allocated and any NVMe and I/OAT devices must be unbound from the native kernel drivers. SPDK includes a script to automate this process on both Linux and FreeBSD. This script should be run as root.

sudo scripts/setup.sh

Users may wish to configure a specific memory size. Below is an example of configuring 8192MB memory.

sudo HUGEMEM=8192 scripts/setup.sh

There are a lot of other environment variables that can be set to configure setup.sh for advanced users. To see the full list, run:

scripts/setup.sh --help

Target applications

After completing the build process, SPDK target applications can be found in spdk/build/bin directory:

  • nvmf_tgt - SPDK NVMe over Fabrics target presents block devices over a fabrics,
  • iscsi_tgt - SPDK iSCSI target runs I/O operations remotely with TCP/IP protocol,
  • vhost - A vhost target provides a local storage service as a process running on a local machine,
  • spdk_tgt - combines capabilities of all three applications.

SPDK runs in a polled mode, which means it continuously checks for operation completions. This approach assures faster response than interrupt mode, but also lessens usefulness of tools like top, which only shows 100% CPU usage for SPDK assigned cores. spdk_top is a program which simulates top application and uses SPDK's JSON RPC interface to present statistics about SPDK threads, pollers and CPU cores as an interactive list.

Example Code

Example code is located in the examples directory. The examples are compiled automatically as part of the build process. Simply call any of the examples with no arguments to see the help output. You'll likely need to run the examples as a privileged user (root) unless you've done additional configuration to grant your user permission to allocate huge pages and map devices through vfio.

Contributing

For additional details on how to get more involved in the community, including contributing code and participating in discussions and other activities, please refer to spdk.io