Files
mscclpp/src/bootstrap/bootstrap.cc
2025-06-03 14:26:27 -07:00

609 lines
20 KiB
C++

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.
#include <sys/resource.h>
#include <cstring>
#include <mscclpp/core.hpp>
#include <mscclpp/errors.hpp>
#include <sstream>
#include <thread>
#include <unordered_map>
#include <vector>
#include "api.h"
#include "debug.h"
#include "socket.h"
#include "utils_internal.hpp"
namespace mscclpp {
static void setFilesLimit() {
rlimit filesLimit;
if (getrlimit(RLIMIT_NOFILE, &filesLimit) != 0) throw SysError("getrlimit failed", errno);
filesLimit.rlim_cur = filesLimit.rlim_max;
if (setrlimit(RLIMIT_NOFILE, &filesLimit) != 0) throw SysError("setrlimit failed", errno);
}
/* Socket Interface Selection type */
enum bootstrapInterface_t { findSubnetIf = -1, dontCareIf = -2 };
struct ExtInfo {
int rank;
int nRanks;
SocketAddress extAddressListenRoot;
SocketAddress extAddressListen;
};
MSCCLPP_API_CPP void Bootstrap::groupBarrier(const std::vector<int>& ranks) {
int dummy = 0;
for (auto rank : ranks) {
if (rank != this->getRank()) {
this->send(static_cast<void*>(&dummy), sizeof(dummy), rank, 0);
}
}
for (auto rank : ranks) {
if (rank != this->getRank()) {
this->recv(static_cast<void*>(&dummy), sizeof(dummy), rank, 0);
}
}
}
MSCCLPP_API_CPP void Bootstrap::send(const std::vector<char>& data, int peer, int tag) {
size_t size = data.size();
send((void*)&size, sizeof(size_t), peer, tag);
send((void*)data.data(), data.size(), peer, tag);
}
MSCCLPP_API_CPP void Bootstrap::recv(std::vector<char>& data, int peer, int tag) {
size_t size;
recv((void*)&size, sizeof(size_t), peer, tag);
data.resize(size);
recv((void*)data.data(), data.size(), peer, tag);
}
struct UniqueIdInternal {
uint64_t magic;
union SocketAddress addr;
};
static_assert(sizeof(UniqueIdInternal) <= sizeof(UniqueId), "UniqueIdInternal is too large to fit into UniqueId");
class TcpBootstrap::Impl {
public:
static UniqueId createUniqueId();
static UniqueId getUniqueId(const UniqueIdInternal& uniqueId);
Impl(int rank, int nRanks);
~Impl();
void initialize(const UniqueId& uniqueId, int64_t timeoutSec);
void initialize(const std::string& ifIpPortTrio, int64_t timeoutSec);
void establishConnections(int64_t timeoutSec);
UniqueId getUniqueId() const;
int getRank();
int getNranks();
int getNranksPerNode();
void allGather(void* allData, int size);
void broadcast(void* data, int size, int root);
void send(void* data, int size, int peer, int tag);
void recv(void* data, int size, int peer, int tag);
void barrier();
void close();
private:
UniqueIdInternal uniqueId_;
int rank_;
int nRanks_;
int nRanksPerNode_;
bool netInitialized;
std::unique_ptr<Socket> listenSockRoot_;
std::unique_ptr<Socket> listenSock_;
std::unique_ptr<Socket> ringRecvSocket_;
std::unique_ptr<Socket> ringSendSocket_;
std::vector<SocketAddress> peerCommAddresses_;
std::vector<int> barrierArr_;
std::unique_ptr<uint32_t> abortFlagStorage_;
volatile uint32_t* abortFlag_;
std::thread rootThread_;
SocketAddress netIfAddr_;
std::unordered_map<std::pair<int, int>, std::shared_ptr<Socket>, PairHash> peerSendSockets_;
std::unordered_map<std::pair<int, int>, std::shared_ptr<Socket>, PairHash> peerRecvSockets_;
void netSend(Socket* sock, const void* data, int size);
void netRecv(Socket* sock, void* data, int size);
std::shared_ptr<Socket> getPeerSendSocket(int peer, int tag);
std::shared_ptr<Socket> getPeerRecvSocket(int peer, int tag);
static void assignPortToUniqueId(UniqueIdInternal& uniqueId);
static void netInit(std::string ipPortPair, std::string interface, SocketAddress& netIfAddr);
void bootstrapCreateRoot();
void bootstrapRoot();
void getRemoteAddresses(Socket* listenSock, std::vector<SocketAddress>& rankAddresses,
std::vector<SocketAddress>& rankAddressesRoot, int& rank);
void sendHandleToPeer(int peer, const std::vector<SocketAddress>& rankAddresses,
const std::vector<SocketAddress>& rankAddressesRoot);
};
UniqueId TcpBootstrap::Impl::createUniqueId() {
UniqueIdInternal uniqueId;
SocketAddress netIfAddr;
netInit("", "", netIfAddr);
getRandomData(&uniqueId.magic, sizeof(uniqueId_.magic));
std::memcpy(&uniqueId.addr, &netIfAddr, sizeof(SocketAddress));
assignPortToUniqueId(uniqueId);
return getUniqueId(uniqueId);
}
UniqueId TcpBootstrap::Impl::getUniqueId(const UniqueIdInternal& uniqueId) {
UniqueId ret;
std::memcpy(&ret, &uniqueId, sizeof(uniqueId));
return ret;
}
TcpBootstrap::Impl::Impl(int rank, int nRanks)
: rank_(rank),
nRanks_(nRanks),
nRanksPerNode_(0),
netInitialized(false),
peerCommAddresses_(nRanks, SocketAddress()),
barrierArr_(nRanks, 0),
abortFlagStorage_(new uint32_t(0)),
abortFlag_(abortFlagStorage_.get()) {}
UniqueId TcpBootstrap::Impl::getUniqueId() const { return getUniqueId(uniqueId_); }
int TcpBootstrap::Impl::getRank() { return rank_; }
int TcpBootstrap::Impl::getNranks() { return nRanks_; }
void TcpBootstrap::Impl::initialize(const UniqueId& uniqueId, int64_t timeoutSec) {
if (!netInitialized) {
netInit("", "", netIfAddr_);
netInitialized = true;
}
std::memcpy(&uniqueId_, &uniqueId, sizeof(uniqueId_));
if (rank_ == 0) {
bootstrapCreateRoot();
}
char line[MAX_IF_NAME_SIZE + 1];
SocketToString(&uniqueId_.addr, line);
INFO(MSCCLPP_INIT, "rank %d nranks %d - connecting to %s", rank_, nRanks_, line);
establishConnections(timeoutSec);
}
void TcpBootstrap::Impl::initialize(const std::string& ifIpPortTrio, int64_t timeoutSec) {
// first check if it is a trio
int nColons = 0;
for (auto c : ifIpPortTrio) {
if (c == ':') {
nColons++;
}
}
std::string ipPortPair = ifIpPortTrio;
std::string interface = "";
if (nColons == 2) {
// we know the <interface>
interface = ifIpPortTrio.substr(0, ipPortPair.find_first_of(':'));
ipPortPair = ifIpPortTrio.substr(ipPortPair.find_first_of(':') + 1);
}
if (!netInitialized) {
netInit(ipPortPair, interface, netIfAddr_);
netInitialized = true;
}
uniqueId_.magic = 0xdeadbeef;
std::memcpy(&uniqueId_.addr, &netIfAddr_, sizeof(SocketAddress));
SocketGetAddrFromString(&uniqueId_.addr, ipPortPair.c_str());
if (rank_ == 0) {
bootstrapCreateRoot();
}
establishConnections(timeoutSec);
}
TcpBootstrap::Impl::~Impl() {
if (abortFlag_) {
*abortFlag_ = 1;
}
if (rootThread_.joinable()) {
rootThread_.join();
}
}
void TcpBootstrap::Impl::getRemoteAddresses(Socket* listenSock, std::vector<SocketAddress>& rankAddresses,
std::vector<SocketAddress>& rankAddressesRoot, int& rank) {
ExtInfo info;
SocketAddress zero;
std::memset(&zero, 0, sizeof(SocketAddress));
{
Socket sock(nullptr, MSCCLPP_SOCKET_MAGIC, SocketTypeUnknown, abortFlag_);
sock.accept(listenSock);
netRecv(&sock, &info, sizeof(info));
}
if (this->nRanks_ != info.nRanks) {
throw Error("Bootstrap Root : mismatch in rank count from procs " + std::to_string(this->nRanks_) + " : " +
std::to_string(info.nRanks),
ErrorCode::InternalError);
}
if (std::memcmp(&zero, &rankAddressesRoot[info.rank], sizeof(SocketAddress)) != 0) {
throw Error("Bootstrap Root : rank " + std::to_string(info.rank) + " of " + std::to_string(this->nRanks_) +
" has already checked in",
ErrorCode::InternalError);
}
// Save the connection handle for that rank
rankAddressesRoot[info.rank] = info.extAddressListenRoot;
rankAddresses[info.rank] = info.extAddressListen;
rank = info.rank;
}
void TcpBootstrap::Impl::sendHandleToPeer(int peer, const std::vector<SocketAddress>& rankAddresses,
const std::vector<SocketAddress>& rankAddressesRoot) {
int next = (peer + 1) % nRanks_;
Socket sock(&rankAddressesRoot[peer], uniqueId_.magic, SocketTypeBootstrap, abortFlag_);
sock.connect();
netSend(&sock, &rankAddresses[next], sizeof(SocketAddress));
}
void TcpBootstrap::Impl::assignPortToUniqueId(UniqueIdInternal& uniqueId) {
std::unique_ptr<Socket> socket = std::make_unique<Socket>(&uniqueId.addr, uniqueId.magic, SocketTypeBootstrap);
socket->bind();
uniqueId.addr = socket->getAddr();
}
void TcpBootstrap::Impl::bootstrapCreateRoot() {
listenSockRoot_ = std::make_unique<Socket>(&uniqueId_.addr, uniqueId_.magic, SocketTypeBootstrap, abortFlag_, 0);
listenSockRoot_->bindAndListen();
uniqueId_.addr = listenSockRoot_->getAddr();
rootThread_ = std::thread([this]() {
try {
bootstrapRoot();
} catch (const std::exception& e) {
if (abortFlag_ && *abortFlag_) return;
throw e;
}
});
}
void TcpBootstrap::Impl::bootstrapRoot() {
int numCollected = 0;
std::vector<SocketAddress> rankAddresses(nRanks_, SocketAddress());
// for initial rank <-> root information exchange
std::vector<SocketAddress> rankAddressesRoot(nRanks_, SocketAddress());
std::memset(rankAddresses.data(), 0, sizeof(SocketAddress) * nRanks_);
std::memset(rankAddressesRoot.data(), 0, sizeof(SocketAddress) * nRanks_);
setFilesLimit();
TRACE(MSCCLPP_INIT, "BEGIN");
/* Receive addresses from all ranks */
do {
int rank;
getRemoteAddresses(listenSockRoot_.get(), rankAddresses, rankAddressesRoot, rank);
++numCollected;
TRACE(MSCCLPP_INIT, "Received connect from rank %d total %d/%d", rank, numCollected, nRanks_);
} while (numCollected < nRanks_ && (!abortFlag_ || *abortFlag_ == 0));
if (abortFlag_ && *abortFlag_) {
TRACE(MSCCLPP_INIT, "ABORTED");
return;
}
TRACE(MSCCLPP_INIT, "COLLECTED ALL %d HANDLES", nRanks_);
// Send the connect handle for the next rank in the AllGather ring
for (int peer = 0; peer < nRanks_; ++peer) {
sendHandleToPeer(peer, rankAddresses, rankAddressesRoot);
}
TRACE(MSCCLPP_INIT, "DONE");
}
void TcpBootstrap::Impl::netInit(std::string ipPortPair, std::string interface, SocketAddress& netIfAddr) {
char netIfName[MAX_IF_NAME_SIZE + 1];
if (!ipPortPair.empty()) {
if (interface != "") {
// we know the <interface>
int ret = FindInterfaces(netIfName, &netIfAddr, MAX_IF_NAME_SIZE, 1, interface.c_str());
if (ret <= 0) throw Error("NET/Socket : No interface named " + interface + " found.", ErrorCode::InternalError);
} else {
// we do not know the <interface> try to match it next
SocketAddress remoteAddr;
SocketGetAddrFromString(&remoteAddr, ipPortPair.c_str());
if (FindInterfaceMatchSubnet(netIfName, &netIfAddr, &remoteAddr, MAX_IF_NAME_SIZE, 1) <= 0) {
throw Error("NET/Socket : No usable listening interface found", ErrorCode::InternalError);
}
}
} else {
int ret = FindInterfaces(netIfName, &netIfAddr, MAX_IF_NAME_SIZE, 1);
if (ret <= 0) {
throw Error("TcpBootstrap : no socket interface found", ErrorCode::InternalError);
}
}
char line[SOCKET_NAME_MAXLEN + MAX_IF_NAME_SIZE + 2];
std::sprintf(line, " %s:", netIfName);
SocketToString(&netIfAddr, line + strlen(line));
INFO(MSCCLPP_INIT, "TcpBootstrap : Using%s", line);
}
#define TIMEOUT(__exp) \
do { \
try { \
__exp; \
} catch (const Error& e) { \
if (e.getErrorCode() == ErrorCode::Timeout) { \
throw Error("TcpBootstrap connection timeout", ErrorCode::Timeout); \
} \
throw; \
} \
} while (0);
void TcpBootstrap::Impl::establishConnections(int64_t timeoutSec) {
const int64_t connectionTimeoutUs = timeoutSec * 1000000;
Timer timer;
SocketAddress nextAddr;
ExtInfo info;
TRACE(MSCCLPP_INIT, "rank %d nranks %d", rank_, nRanks_);
auto getLeftTime = [&]() {
if (connectionTimeoutUs < 0) {
// no timeout: always return a large number
return int64_t(1e9);
}
int64_t timeout = connectionTimeoutUs - timer.elapsed();
if (timeout <= 0) throw Error("TcpBootstrap connection timeout", ErrorCode::Timeout);
return timeout;
};
info.rank = rank_;
info.nRanks = nRanks_;
uint64_t magic = uniqueId_.magic;
// Create socket for other ranks to contact me
listenSock_ = std::make_unique<Socket>(&netIfAddr_, magic, SocketTypeBootstrap, abortFlag_);
listenSock_->bindAndListen();
info.extAddressListen = listenSock_->getAddr();
{
// Create socket for root to contact me
Socket lsock(&netIfAddr_, magic, SocketTypeBootstrap, abortFlag_);
lsock.bindAndListen();
info.extAddressListenRoot = lsock.getAddr();
// stagger connection times to avoid an overload of the root
auto randomSleep = [](int rank) {
timespec tv;
tv.tv_sec = rank / 1000;
tv.tv_nsec = 1000000 * (rank % 1000);
TRACE(MSCCLPP_INIT, "rank %d delaying connection to root by %ld msec", rank, rank);
(void)nanosleep(&tv, NULL);
};
if (nRanks_ > 128) {
randomSleep(rank_);
}
// send info on my listening socket to root
{
Socket sock(&uniqueId_.addr, magic, SocketTypeBootstrap, abortFlag_);
TIMEOUT(sock.connect(getLeftTime()));
netSend(&sock, &info, sizeof(info));
}
// get info on my "next" rank in the bootstrap ring from root
{
Socket sock(nullptr, MSCCLPP_SOCKET_MAGIC, SocketTypeUnknown, abortFlag_);
TIMEOUT(sock.accept(&lsock, getLeftTime()));
netRecv(&sock, &nextAddr, sizeof(SocketAddress));
}
}
ringSendSocket_ = std::make_unique<Socket>(&nextAddr, magic, SocketTypeBootstrap, abortFlag_);
TIMEOUT(ringSendSocket_->connect(getLeftTime()));
// Accept the connect request from the previous rank in the AllGather ring
ringRecvSocket_ = std::make_unique<Socket>(nullptr, MSCCLPP_SOCKET_MAGIC, SocketTypeUnknown, abortFlag_);
TIMEOUT(ringRecvSocket_->accept(listenSock_.get(), getLeftTime()));
// AllGather all listen handlers
peerCommAddresses_[rank_] = listenSock_->getAddr();
allGather(peerCommAddresses_.data(), sizeof(SocketAddress));
TRACE(MSCCLPP_INIT, "rank %d nranks %d - DONE", rank_, nRanks_);
}
int TcpBootstrap::Impl::getNranksPerNode() {
if (nRanksPerNode_ > 0) return nRanksPerNode_;
int nRanksPerNode = 0;
bool useIpv4 = peerCommAddresses_[rank_].sa.sa_family == AF_INET;
for (int i = 0; i < nRanks_; i++) {
if (useIpv4) {
if (peerCommAddresses_[i].sin.sin_addr.s_addr == peerCommAddresses_[rank_].sin.sin_addr.s_addr) {
nRanksPerNode++;
}
} else {
if (std::memcmp(&(peerCommAddresses_[i].sin6.sin6_addr), &(peerCommAddresses_[rank_].sin6.sin6_addr),
sizeof(in6_addr)) == 0) {
nRanksPerNode++;
}
}
}
nRanksPerNode_ = nRanksPerNode;
return nRanksPerNode_;
}
void TcpBootstrap::Impl::allGather(void* allData, int size) {
char* data = static_cast<char*>(allData);
int rank = rank_;
int nRanks = nRanks_;
TRACE(MSCCLPP_INIT, "rank %d nranks %d size %d", rank, nRanks, size);
/* Simple ring based AllGather
* At each step i receive data from (rank-i-1) from left
* and send previous step's data from (rank-i) to right
*/
for (int i = 0; i < nRanks - 1; i++) {
size_t rSlice = (rank - i - 1 + nRanks) % nRanks;
size_t sSlice = (rank - i + nRanks) % nRanks;
// Send slice to the right
netSend(ringSendSocket_.get(), data + sSlice * size, size);
// Recv slice from the left
netRecv(ringRecvSocket_.get(), data + rSlice * size, size);
}
TRACE(MSCCLPP_INIT, "rank %d nranks %d size %d - DONE", rank, nRanks, size);
}
void TcpBootstrap::Impl::broadcast(void* data, int size, int root) {
int rank = rank_;
int nRanks = nRanks_;
if (nRanks == 1) return;
TRACE(MSCCLPP_INIT, "rank %d nranks %d root %d size %d", rank, nRanks, root, size);
/*Ring-based broadcast, propagate data in nRanks-1 steps*/
// For ring-based broadcast, propagate data in nRanks-1 steps
for (int step = 0; step < nRanks - 1; step++) {
if (rank == root) {
// Root sends data to next rank in first step
if (step == 0) {
netSend(ringSendSocket_.get(), data, size);
}
} else {
// Calculate when this rank should receive data
int receiveStep = (rank - root - 1 + nRanks) % nRanks;
if (step == receiveStep) {
// Receive from previous rank
netRecv(ringRecvSocket_.get(), data, size);
// Forward to next rank (if not last step)
if (step < nRanks - 2) {
netSend(ringSendSocket_.get(), data, size);
}
}
}
}
TRACE(MSCCLPP_INIT, "rank %d nranks %d root %d size %d - DONE", rank, nRanks, root, size);
}
std::shared_ptr<Socket> TcpBootstrap::Impl::getPeerSendSocket(int peer, int tag) {
auto it = peerSendSockets_.find(std::make_pair(peer, tag));
if (it != peerSendSockets_.end()) {
return it->second;
}
auto sock = std::make_shared<Socket>(&peerCommAddresses_[peer], uniqueId_.magic, SocketTypeBootstrap, abortFlag_);
sock->connect();
netSend(sock.get(), &rank_, sizeof(int));
netSend(sock.get(), &tag, sizeof(int));
peerSendSockets_[std::make_pair(peer, tag)] = sock;
return sock;
}
std::shared_ptr<Socket> TcpBootstrap::Impl::getPeerRecvSocket(int peer, int tag) {
auto it = peerRecvSockets_.find(std::make_pair(peer, tag));
if (it != peerRecvSockets_.end()) {
return it->second;
}
for (;;) {
auto sock = std::make_shared<Socket>(nullptr, MSCCLPP_SOCKET_MAGIC, SocketTypeUnknown, abortFlag_);
sock->accept(listenSock_.get());
int recvPeer, recvTag;
netRecv(sock.get(), &recvPeer, sizeof(int));
netRecv(sock.get(), &recvTag, sizeof(int));
peerRecvSockets_[std::make_pair(recvPeer, recvTag)] = sock;
if (recvPeer == peer && recvTag == tag) {
return sock;
}
// TODO(chhwang): set an exit condition or timeout
}
}
void TcpBootstrap::Impl::netSend(Socket* sock, const void* data, int size) {
sock->send(&size, sizeof(int));
sock->send(const_cast<void*>(data), size);
}
void TcpBootstrap::Impl::netRecv(Socket* sock, void* data, int size) {
int recvSize;
sock->recv(&recvSize, sizeof(int));
if (recvSize > size) {
std::stringstream ss;
ss << "Message truncated : received " << recvSize << " bytes instead of " << size;
throw Error(ss.str(), ErrorCode::InvalidUsage);
}
sock->recv(data, std::min(recvSize, size));
}
void TcpBootstrap::Impl::send(void* data, int size, int peer, int tag) {
auto sock = getPeerSendSocket(peer, tag);
netSend(sock.get(), data, size);
}
void TcpBootstrap::Impl::recv(void* data, int size, int peer, int tag) {
auto sock = getPeerRecvSocket(peer, tag);
netRecv(sock.get(), data, size);
}
void TcpBootstrap::Impl::barrier() { allGather(barrierArr_.data(), sizeof(int)); }
void TcpBootstrap::Impl::close() {
listenSockRoot_.reset(nullptr);
listenSock_.reset(nullptr);
ringRecvSocket_.reset(nullptr);
ringSendSocket_.reset(nullptr);
peerSendSockets_.clear();
peerRecvSockets_.clear();
}
MSCCLPP_API_CPP UniqueId TcpBootstrap::createUniqueId() { return Impl::createUniqueId(); }
MSCCLPP_API_CPP TcpBootstrap::TcpBootstrap(int rank, int nRanks) { pimpl_ = std::make_unique<Impl>(rank, nRanks); }
MSCCLPP_API_CPP UniqueId TcpBootstrap::getUniqueId() const { return pimpl_->getUniqueId(); }
MSCCLPP_API_CPP int TcpBootstrap::getRank() const { return pimpl_->getRank(); }
MSCCLPP_API_CPP int TcpBootstrap::getNranks() const { return pimpl_->getNranks(); }
MSCCLPP_API_CPP int TcpBootstrap::getNranksPerNode() const { return pimpl_->getNranksPerNode(); }
MSCCLPP_API_CPP void TcpBootstrap::send(void* data, int size, int peer, int tag) {
pimpl_->send(data, size, peer, tag);
}
MSCCLPP_API_CPP void TcpBootstrap::recv(void* data, int size, int peer, int tag) {
pimpl_->recv(data, size, peer, tag);
}
MSCCLPP_API_CPP void TcpBootstrap::allGather(void* allData, int size) { pimpl_->allGather(allData, size); }
MSCCLPP_API_CPP void TcpBootstrap::broadcast(void* data, int size, int root) { pimpl_->broadcast(data, size, root); }
MSCCLPP_API_CPP void TcpBootstrap::initialize(UniqueId uniqueId, int64_t timeoutSec) {
pimpl_->initialize(uniqueId, timeoutSec);
}
MSCCLPP_API_CPP void TcpBootstrap::initialize(const std::string& ipPortPair, int64_t timeoutSec) {
pimpl_->initialize(ipPortPair, timeoutSec);
}
MSCCLPP_API_CPP void TcpBootstrap::barrier() { pimpl_->barrier(); }
MSCCLPP_API_CPP TcpBootstrap::~TcpBootstrap() { pimpl_->close(); }
} // namespace mscclpp