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arangodb/arangod/Cluster/ServerState.cpp

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////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2018 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#include "ServerState.h"
#include <algorithm>
#include <iomanip>
#include <regex>
#include <unordered_map>
#include <boost/uuid/uuid.hpp>
#include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp>
#include "Agency/AgencyComm.h"
#include "ApplicationFeatures/ApplicationServer.h"
#include "Basics/FileUtils.h"
#include "Basics/ReadLocker.h"
#include "Basics/VelocyPackHelper.h"
#include "Basics/WriteLocker.h"
#include "Cluster/ClusterInfo.h"
#include "Cluster/ResultT.h"
#include "Logger/Logger.h"
#include "Rest/Version.h"
#include "RestServer/DatabaseFeature.h"
#include "RestServer/DatabasePathFeature.h"
#include "StorageEngine/EngineSelectorFeature.h"
#include "VocBase/ticks.h"
#include <velocypack/Iterator.h>
#include <velocypack/velocypack-aliases.h>
using namespace arangodb;
using namespace arangodb::basics;
namespace {
// whenever the format of the generated UUIDs changes, please make sure to
// adjust this regex too!
std::regex const uuidRegex("^(SNGL|CRDN|PRMR|AGNT)-[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$");
}
static constexpr char const* currentServersRegisteredPref =
"/Current/ServersRegistered/";
////////////////////////////////////////////////////////////////////////////////
/// @brief single instance of ServerState - will live as long as the server is
/// running
////////////////////////////////////////////////////////////////////////////////
static ServerState Instance;
ServerState::ServerState()
: _role(RoleEnum::ROLE_UNDEFINED),
_lock(),
_id(),
_shortId(0),
_rebootId(0),
_javaScriptStartupPath(),
_myEndpoint(),
_advertisedEndpoint(),
_host(),
_state(STATE_UNDEFINED),
_initialized(false),
_foxxmasterQueueupdate(false) {
setRole(ROLE_UNDEFINED);
}
void ServerState::findHost(std::string const& fallback) {
// Compute a string identifying the host on which we are running, note
// that this is more complicated than immediately obvious, because we
// could sit in a container which is deployed by Kubernetes or Mesos or
// some other orchestration framework:
// the following is set by Mesos or by an administrator:
char* p = getenv("HOST");
if (p != nullptr) {
_host = p;
return;
}
// the following is set by Kubernetes when using the downward API:
p = getenv("NODE_NAME");
if (p != nullptr) {
_host = p;
return;
}
// Now look at the contents of the file /etc/machine-id, if it exists:
std::string name = "/etc/machine-id";
if (arangodb::basics::FileUtils::exists(name)) {
try {
_host = arangodb::basics::FileUtils::slurp(name);
while (!_host.empty() &&
(_host.back() == '\r' || _host.back() == '\n' || _host.back() == ' ')) {
_host.erase(_host.size() - 1);
}
if (!_host.empty()) {
return;
}
} catch (...) {
}
}
#ifdef __APPLE__
static_assert(sizeof(uuid_t) == 16, "");
uuid_t localUuid;
struct timespec timeout;
timeout.tv_sec = 5;
timeout.tv_nsec = 0;
int res = gethostuuid(localUuid, &timeout);
if (res == 0) {
_host = StringUtils::encodeHex(reinterpret_cast<char*>(localUuid), sizeof(uuid_t));
return;
}
#endif
// Finally, as a last resort, take the fallback, coming from
// the ClusterFeature with the value of --cluster.my-address
// or by the AgencyFeature with the value of --agency.my-address:
_host = fallback;
}
ServerState::~ServerState() {}
////////////////////////////////////////////////////////////////////////////////
/// @brief create the (sole) instance
////////////////////////////////////////////////////////////////////////////////
ServerState* ServerState::instance() { return &Instance; }
////////////////////////////////////////////////////////////////////////////////
/// @brief get the string representation of a role
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::roleToString(ServerState::RoleEnum role) {
switch (role) {
case ROLE_UNDEFINED:
return "UNDEFINED";
case ROLE_SINGLE:
return "SINGLE";
case ROLE_DBSERVER:
return "PRIMARY";
case ROLE_COORDINATOR:
return "COORDINATOR";
case ROLE_AGENT:
return "AGENT";
}
TRI_ASSERT(false);
return "";
}
std::string ServerState::roleToShortString(ServerState::RoleEnum role) {
// whenever anything here changes, please make sure to
// adjust ::uuidRegex too!
switch (role) {
case ROLE_UNDEFINED:
return "NONE";
case ROLE_SINGLE:
return "SNGL";
case ROLE_DBSERVER:
return "PRMR";
case ROLE_COORDINATOR:
return "CRDN";
case ROLE_AGENT:
return "AGNT";
}
TRI_ASSERT(false);
return "";
}
////////////////////////////////////////////////////////////////////////////////
/// @brief convert a string to a role
////////////////////////////////////////////////////////////////////////////////
ServerState::RoleEnum ServerState::stringToRole(std::string const& value) {
if (value == "SINGLE") {
return ROLE_SINGLE;
} else if (value == "PRIMARY" || value == "DBSERVER") {
// note: DBSERVER is an alias for PRIMARY
// internally and in all API values returned we will still use PRIMARY
// for compatibility reasons
return ROLE_DBSERVER;
} else if (value == "COORDINATOR") {
return ROLE_COORDINATOR;
} else if (value == "AGENT") {
return ROLE_AGENT;
}
return ROLE_UNDEFINED;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the string representation of a state
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::stateToString(StateEnum state) {
// TODO MAX: cleanup
switch (state) {
case STATE_UNDEFINED:
return "UNDEFINED";
case STATE_STARTUP:
return "STARTUP";
case STATE_STOPPING:
return "STOPPING";
case STATE_STOPPED:
return "STOPPED";
case STATE_SERVING:
return "SERVING";
case STATE_SHUTDOWN:
return "SHUTDOWN";
}
TRI_ASSERT(false);
return "";
}
////////////////////////////////////////////////////////////////////////////////
/// @brief convert a string representation to a state
////////////////////////////////////////////////////////////////////////////////
ServerState::StateEnum ServerState::stringToState(std::string const& value) {
if (value == "SHUTDOWN") {
return STATE_SHUTDOWN;
}
// TODO MAX: do we need to understand other states, too?
return STATE_UNDEFINED;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief convert a mode to string
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::modeToString(Mode mode) {
switch (mode) {
case Mode::DEFAULT:
return "default";
case Mode::MAINTENANCE:
return "maintenance";
case Mode::TRYAGAIN:
return "tryagain";
case Mode::REDIRECT:
return "redirect";
case Mode::INVALID:
return "invalid";
}
TRI_ASSERT(false);
return "";
}
////////////////////////////////////////////////////////////////////////////////
/// @brief convert string to mode
////////////////////////////////////////////////////////////////////////////////
ServerState::Mode ServerState::stringToMode(std::string const& value) {
if (value == "default") {
return Mode::DEFAULT;
} else if (value == "maintenance") {
return Mode::MAINTENANCE;
} else if (value == "tryagain") {
return Mode::TRYAGAIN;
} else if (value == "redirect") {
return Mode::REDIRECT;
} else {
return Mode::INVALID;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief current server mode
////////////////////////////////////////////////////////////////////////////////
static std::atomic<ServerState::Mode> _serverstate_mode(ServerState::Mode::DEFAULT);
////////////////////////////////////////////////////////////////////////////////
/// @brief atomically load current server mode
////////////////////////////////////////////////////////////////////////////////
ServerState::Mode ServerState::mode() {
return _serverstate_mode.load(std::memory_order_acquire);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief change server mode, returns previously set mode
////////////////////////////////////////////////////////////////////////////////
ServerState::Mode ServerState::setServerMode(ServerState::Mode value) {
//_serverMode.store(value, std::memory_order_release);
if (_serverstate_mode.load(std::memory_order_acquire) != value) {
return _serverstate_mode.exchange(value, std::memory_order_release);
}
return value;
}
static std::atomic<bool> _serverstate_readonly(false);
bool ServerState::readOnly() {
return _serverstate_readonly.load(std::memory_order_acquire);
}
/// @brief set server read-only
bool ServerState::setReadOnly(bool ro) {
return _serverstate_readonly.exchange(ro, std::memory_order_release);
}
// ============ Instance methods =================
/// @brief unregister this server with the agency
bool ServerState::unregister() {
TRI_ASSERT(!getId().empty());
TRI_ASSERT(AgencyCommManager::isEnabled());
std::string const& id = getId();
std::vector<AgencyOperation> operations;
const std::string agencyListKey = roleToAgencyListKey(loadRole());
operations.push_back(AgencyOperation("Plan/" + agencyListKey + "/" + id,
AgencySimpleOperationType::DELETE_OP));
operations.push_back(AgencyOperation("Current/" + agencyListKey + "/" + id,
AgencySimpleOperationType::DELETE_OP));
operations.push_back(AgencyOperation("Current/ServersKnown/" + id,
AgencySimpleOperationType::DELETE_OP));
operations.push_back(AgencyOperation("Plan/Version", AgencySimpleOperationType::INCREMENT_OP));
operations.push_back(AgencyOperation("Current/Version",
AgencySimpleOperationType::INCREMENT_OP));
AgencyWriteTransaction unregisterTransaction(operations);
AgencyComm comm;
AgencyCommResult r = comm.sendTransactionWithFailover(unregisterTransaction);
return r.successful();
}
ResultT<uint64_t> ServerState::readRebootIdFromAgency(AgencyComm& comm) {
TRI_ASSERT(!_id.empty());
std::string rebootIdPath = "Current/ServersKnown/" + _id + "/rebootId";
AgencyCommResult result = comm.getValues(rebootIdPath);
if (!result.successful()) {
LOG_TOPIC("762ed", WARN, Logger::CLUSTER)
<< "Could not read back " << rebootIdPath;
return ResultT<uint64_t>::error(TRI_ERROR_INTERNAL, "could not read rebootId from agency");
}
auto slicePath = AgencyCommManager::slicePath(rebootIdPath);
auto valueSlice = result.slice()[0].get(slicePath);
if (!valueSlice.isInteger()) {
LOG_TOPIC("38a4a", WARN, Logger::CLUSTER)
<< "rebootId is not an integer";
return ResultT<uint64_t>::error(TRI_ERROR_INTERNAL, "rebootId is not an integer");
}
return ResultT<uint64_t>::success(valueSlice.getNumericValue<uint64_t>());
}
////////////////////////////////////////////////////////////////////////////////
/// @brief try to integrate into a cluster
////////////////////////////////////////////////////////////////////////////////
bool ServerState::integrateIntoCluster(ServerState::RoleEnum role,
std::string const& myEndpoint,
std::string const& advEndpoint) {
WRITE_LOCKER(writeLocker, _lock);
AgencyComm comm;
if (!checkEngineEquality(comm)) {
LOG_TOPIC("1e2da", FATAL, arangodb::Logger::ENGINES)
<< "the usage of different storage engines in the "
<< "cluster is unsupported and may cause issues";
return false;
}
// if (have persisted id) {
// use the persisted id
// } else {
// if (myLocalId not empty) {
// lookup in agency
// if (found) {
// persist id
// }
// }
// if (id still not set) {
// generate and persist new id
// }
std::string id;
bool hadPersistedId = hasPersistedId();
if (!hadPersistedId) {
id = generatePersistedId(role);
LOG_TOPIC("0d924", INFO, Logger::CLUSTER) << "Fresh start. Persisting new UUID " << id;
} else {
id = getPersistedId();
LOG_TOPIC("db3ce", DEBUG, Logger::CLUSTER) << "Restarting with persisted UUID " << id;
}
setId(id);
_myEndpoint = myEndpoint;
_advertisedEndpoint = advEndpoint;
TRI_ASSERT(!_myEndpoint.empty());
if (!registerAtAgencyPhase1(comm, role)) {
return false;
}
Logger::setRole(roleToString(role)[0]);
_role.store(role, std::memory_order_release);
LOG_TOPIC("61a39", DEBUG, Logger::CLUSTER) << "We successfully announced ourselves as "
<< roleToString(role) << " and our id is " << id;
// now overwrite the entry in /Current/ServersRegistered/<myId>
bool registered = registerAtAgencyPhase2(comm, hadPersistedId);
if (!registered) {
return false;
}
// now check the configuration of the different servers for duplicate endpoints
AgencyCommResult result = comm.getValues(currentServersRegisteredPref);
if (result.successful()) {
auto slicePath = AgencyCommManager::slicePath(currentServersRegisteredPref);
auto valueSlice = result.slice()[0].get(slicePath);
if (valueSlice.isObject()) {
// map from server UUID to endpoint
std::unordered_map<std::string, std::string> endpoints;
for (auto const& it : VPackObjectIterator(valueSlice)) {
std::string const serverId = it.key.copyString();
if (!isUuid(serverId)) {
continue;
}
if (!it.value.isObject()) {
continue;
}
VPackSlice endpointSlice = it.value.get("endpoint");
if (!endpointSlice.isString()) {
continue;
}
auto it2 = endpoints.emplace(endpointSlice.copyString(), serverId);
if (!it2.second && it2.first->first != serverId) {
// duplicate entry!
LOG_TOPIC("9a134", WARN, Logger::CLUSTER)
<< "found duplicate server entry for endpoint '"
<< endpointSlice.copyString() << "', already used by other server " << it2.first->second
<< ". it looks like this is a (mis)configuration issue";
// anyway, continue with startup
}
}
}
}
return true;
}
/// @brief whether or not "value" is a server UUID
bool ServerState::isUuid(std::string const& value) const {
// whenever the format of the generated UUIDs changes, please make sure to
// adjust ::uuidRegex too!
return std::regex_match(value, ::uuidRegex);
}
//////////////////////////////////////////////////////////////////////////////
/// @brief get the key for a role in the agency
//////////////////////////////////////////////////////////////////////////////
std::string ServerState::roleToAgencyListKey(ServerState::RoleEnum role) {
return roleToAgencyKey(role) + "s"; // lol
}
std::string ServerState::roleToAgencyKey(ServerState::RoleEnum role) {
switch (role) {
case ROLE_DBSERVER:
return "DBServer";
case ROLE_COORDINATOR:
return "Coordinator";
case ROLE_SINGLE:
return "Single";
case ROLE_UNDEFINED:
case ROLE_AGENT: {
TRI_ASSERT(false);
}
}
return "INVALID_CLUSTER_ROLE";
}
void mkdir(std::string const& path) {
if (!TRI_IsDirectory(path.c_str())) {
if (!arangodb::basics::FileUtils::createDirectory(path)) {
LOG_TOPIC("626e8", FATAL, arangodb::Logger::CLUSTER)
<< "Couldn't create file directory " << path << " (UUID)";
FATAL_ERROR_EXIT();
}
}
}
std::string ServerState::getUuidFilename() const {
auto dbpath = application_features::ApplicationServer::getFeature<DatabasePathFeature>(
"DatabasePath");
TRI_ASSERT(dbpath != nullptr);
return FileUtils::buildFilename(dbpath->directory(), "UUID");
}
bool ServerState::hasPersistedId() {
std::string uuidFilename = getUuidFilename();
return FileUtils::exists(uuidFilename);
}
bool ServerState::writePersistedId(std::string const& id) {
std::string uuidFilename = getUuidFilename();
// try to create underlying directory
int error;
FileUtils::createDirectory(FileUtils::dirname(uuidFilename), &error);
try {
arangodb::basics::FileUtils::spit(uuidFilename, id, true);
} catch (arangodb::basics::Exception const& ex) {
LOG_TOPIC("f2f70", FATAL, arangodb::Logger::FIXME)
<< "Cannot write UUID file '" << uuidFilename << "': " << ex.what();
FATAL_ERROR_EXIT();
}
return true;
}
std::string ServerState::generatePersistedId(RoleEnum const& role) {
// whenever the format of the generated UUID changes, please make sure to
// adjust ::uuidRegex too!
std::string id =
roleToShortString(role) + "-" + to_string(boost::uuids::random_generator()());
writePersistedId(id);
return id;
}
std::string ServerState::getPersistedId() {
std::string uuidFilename = getUuidFilename();
if (hasPersistedId()) {
try {
auto uuidBuf = arangodb::basics::FileUtils::slurp(uuidFilename);
basics::StringUtils::trimInPlace(uuidBuf);
if (!uuidBuf.empty()) {
return uuidBuf;
}
} catch (arangodb::basics::Exception const& ex) {
LOG_TOPIC("8dd60", FATAL, arangodb::Logger::CLUSTER)
<< "Couldn't read UUID file '" << uuidFilename << "' - " << ex.what();
FATAL_ERROR_EXIT();
}
}
LOG_TOPIC("b3923", FATAL, Logger::STARTUP) << "Couldn't open UUID file '" << uuidFilename << "'";
FATAL_ERROR_EXIT();
}
/// @brief check equality of engines with other registered servers
bool ServerState::checkEngineEquality(AgencyComm& comm) {
std::string engineName = EngineSelectorFeature::engineName();
AgencyCommResult result = comm.getValues(currentServersRegisteredPref);
if (result.successful()) { // no error if we cannot reach agency directly
auto slicePath = AgencyCommManager::slicePath(currentServersRegisteredPref);
VPackSlice servers = result.slice()[0].get(slicePath);
if (!servers.isObject()) {
return true; // do not do anything harsh here
}
for (VPackObjectIterator::ObjectPair pair : VPackObjectIterator(servers)) {
if (pair.value.isObject()) {
VPackSlice engineStr = pair.value.get("engine");
if (engineStr.isString() && !engineStr.isEqualString(engineName)) {
return false;
}
}
}
}
return true;
}
//////////////////////////////////////////////////////////////////////////////
/// @brief create an id for a specified role
//////////////////////////////////////////////////////////////////////////////
bool ServerState::registerAtAgencyPhase1(AgencyComm& comm, ServerState::RoleEnum const& role) {
std::string const agencyListKey = roleToAgencyListKey(role);
std::string const latestIdKey = "Latest" + roleToAgencyKey(role) + "Id";
VPackBuilder builder;
builder.add(VPackValue("none"));
AgencyCommResult createResult;
AgencyCommResult result = comm.getValues("Plan/" + agencyListKey);
if (!result.successful()) {
LOG_TOPIC("0f327", FATAL, Logger::STARTUP)
<< "Couldn't fetch Plan/" << agencyListKey << " from agency. "
<< " Agency is not initialized?";
return false;
}
VPackSlice servers = result.slice()[0].get(
std::vector<std::string>({AgencyCommManager::path(), "Plan", agencyListKey}));
if (!servers.isObject()) {
LOG_TOPIC("6507f", FATAL, Logger::STARTUP) << "Plan/" << agencyListKey << " in agency is no object. "
<< "Agency not initialized?";
return false;
}
std::string planUrl = "Plan/" + agencyListKey + "/" + _id;
std::string currentUrl = "Current/" + agencyListKey + "/" + _id;
AgencyWriteTransaction preg(
{AgencyOperation(planUrl, AgencyValueOperationType::SET, builder.slice()),
AgencyOperation("Plan/Version", AgencySimpleOperationType::INCREMENT_OP)},
AgencyPrecondition(planUrl, AgencyPrecondition::Type::EMPTY, true));
// ok to fail..if it failed we are already registered
comm.sendTransactionWithFailover(preg, 0.0);
AgencyWriteTransaction creg(
{AgencyOperation(currentUrl, AgencyValueOperationType::SET, builder.slice()),
AgencyOperation("Current/Version", AgencySimpleOperationType::INCREMENT_OP)},
AgencyPrecondition(currentUrl, AgencyPrecondition::Type::EMPTY, true));
// ok to fail..if it failed we are already registered
AgencyCommResult res = comm.sendTransactionWithFailover(creg, 0.0);
// coordinator is already/still registered from an previous unclean shutdown;
// must establish a new short ID
bool forceChangeShortId = isCoordinator(role);
std::string targetIdPath = "Target/" + latestIdKey;
std::string targetUrl = "Target/MapUniqueToShortID/" + _id;
size_t attempts{0};
while (attempts++ < 300) {
AgencyReadTransaction readValueTrx(
std::vector<std::string>{AgencyCommManager::path(targetIdPath),
AgencyCommManager::path(targetUrl)});
AgencyCommResult result = comm.sendTransactionWithFailover(readValueTrx, 0.0);
if (!result.successful()) {
LOG_TOPIC("8d5ff", WARN, Logger::CLUSTER)
<< "Couldn't fetch " << targetIdPath << " and " << targetUrl;
std::this_thread::sleep_for(std::chrono::seconds(1));
continue;
}
VPackSlice mapSlice = result.slice()[0].get(std::vector<std::string>(
{AgencyCommManager::path(), "Target", "MapUniqueToShortID", _id}));
// already registered
if (!mapSlice.isNone() && !forceChangeShortId) {
VPackSlice s = mapSlice.get("TransactionID");
if (s.isNumber()) {
uint32_t shortId = s.getNumericValue<uint32_t>();
setShortId(shortId);
LOG_TOPIC("c6fb2", DEBUG, Logger::CLUSTER) << "restored short id " << shortId << " from agency";
} else {
LOG_TOPIC("13c13", WARN, Logger::CLUSTER)
<< "unable to restore short id from agency";
}
return true;
}
VPackSlice latestIdSlice = result.slice()[0].get(
std::vector<std::string>({AgencyCommManager::path(), "Target", latestIdKey}));
uint32_t num = 0;
std::unique_ptr<AgencyPrecondition> latestIdPrecondition;
VPackBuilder latestIdBuilder;
if (latestIdSlice.isNumber()) {
num = latestIdSlice.getNumber<uint32_t>();
latestIdBuilder.add(VPackValue(num));
latestIdPrecondition.reset(
new AgencyPrecondition(targetIdPath, AgencyPrecondition::Type::VALUE,
latestIdBuilder.slice()));
} else {
latestIdPrecondition.reset(
new AgencyPrecondition(targetIdPath, AgencyPrecondition::Type::EMPTY, true));
}
VPackBuilder localIdBuilder;
{
VPackObjectBuilder b(&localIdBuilder);
localIdBuilder.add("TransactionID", VPackValue(num + 1));
std::stringstream ss; // ShortName
size_t width = std::max(std::to_string(num + 1).size(), static_cast<size_t>(4));
ss << roleToAgencyKey(role) << std::setw(width) << std::setfill('0') << num + 1;
localIdBuilder.add("ShortName", VPackValue(ss.str()));
}
std::vector<AgencyOperation> operations;
std::vector<AgencyPrecondition> preconditions;
operations.push_back(AgencyOperation(targetIdPath, AgencySimpleOperationType::INCREMENT_OP));
operations.push_back(AgencyOperation(targetUrl, AgencyValueOperationType::SET,
localIdBuilder.slice()));
preconditions.push_back(*(latestIdPrecondition.get()));
preconditions.push_back(AgencyPrecondition(targetUrl, AgencyPrecondition::Type::EMPTY,
mapSlice.isNone()));
AgencyWriteTransaction trx(operations, preconditions);
result = comm.sendTransactionWithFailover(trx, 0.0);
if (result.successful()) {
setShortId(num + 1); // save short ID for generating server-specific ticks
return true;
}
std::this_thread::sleep_for(std::chrono::seconds(1));
}
LOG_TOPIC("309d7", FATAL, Logger::STARTUP) << "Couldn't register shortname for " << _id;
return false;
}
bool ServerState::registerAtAgencyPhase2(AgencyComm& comm, bool const hadPersistedId) {
TRI_ASSERT(!_id.empty() && !_myEndpoint.empty());
std::string const serverRegistrationPath = currentServersRegisteredPref + _id;
std::string const rebootIdPath = "/Current/ServersKnown/" + _id + "/rebootId";
// If we generated a new UUID, this *must not* exist in the Agency, so we
// should fail to register.
std::vector<AgencyPrecondition> pre;
if (!hadPersistedId) {
pre.emplace_back(AgencyPrecondition(rebootIdPath, AgencyPrecondition::Type::EMPTY, true));
}
while (!application_features::ApplicationServer::isStopping()) {
VPackBuilder builder;
{
VPackObjectBuilder b(&builder);
builder.add("endpoint", VPackValue(_myEndpoint));
builder.add("advertisedEndpoint", VPackValue(_advertisedEndpoint));
builder.add("host", VPackValue(getHost()));
builder.add("version", VPackValue(rest::Version::getNumericServerVersion()));
builder.add("versionString", VPackValue(rest::Version::getServerVersion()));
builder.add("engine", VPackValue(EngineSelectorFeature::engineName()));
}
AgencyWriteTransaction trx(
{AgencyOperation(serverRegistrationPath, AgencyValueOperationType::SET,
builder.slice()),
AgencyOperation(rebootIdPath, AgencySimpleOperationType::INCREMENT_OP),
AgencyOperation("Current/Version", AgencySimpleOperationType::INCREMENT_OP)},
pre);
auto result = comm.sendTransactionWithFailover(trx, 0.0);
if (result.successful()) {
break; // Continue below to read back the rebootId
} else {
LOG_TOPIC("ba205", WARN, arangodb::Logger::CLUSTER)
<< "failed to register server in agency: http code: " << result.httpCode()
<< ", body: '" << result.body() << "', retrying ...";
}
std::this_thread::sleep_for(std::chrono::seconds(1));
}
// if we left the above retry loop because the server is stopping
// we'll skip this and return false right away.
while (!application_features::ApplicationServer::isStopping()) {
auto result = readRebootIdFromAgency(comm);
if (result) {
setRebootId(result.get());
return true;
}
std::this_thread::sleep_for(std::chrono::seconds(1));
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set the server role
////////////////////////////////////////////////////////////////////////////////
void ServerState::setRole(ServerState::RoleEnum role) {
Logger::setRole(roleToString(role)[0]);
_role.store(role, std::memory_order_release);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the server id
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::getId() const {
std::lock_guard<std::mutex> guard(_idLock);
return _id;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set the server id
////////////////////////////////////////////////////////////////////////////////
void ServerState::setId(std::string const& id) {
if (id.empty()) {
return;
}
std::lock_guard<std::mutex> guard(_idLock);
_id = id;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the short server id
////////////////////////////////////////////////////////////////////////////////
uint32_t ServerState::getShortId() const {
return _shortId.load(std::memory_order_relaxed);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set the short server id
////////////////////////////////////////////////////////////////////////////////
void ServerState::setShortId(uint32_t id) {
if (id == 0) {
return;
}
_shortId.store(id, std::memory_order_relaxed);
}
uint64_t ServerState::getRebootId() const {
TRI_ASSERT(_rebootId > 0);
return _rebootId;
}
void ServerState::setRebootId(uint64_t rebootId) {
TRI_ASSERT(rebootId > 0);
_rebootId = rebootId;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the server address
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::getEndpoint() {
READ_LOCKER(readLocker, _lock);
return _myEndpoint;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the server advertised endpoint
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::getAdvertisedEndpoint() {
READ_LOCKER(readLocker, _lock);
return _advertisedEndpoint;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the current state
////////////////////////////////////////////////////////////////////////////////
ServerState::StateEnum ServerState::getState() {
READ_LOCKER(readLocker, _lock);
return _state;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set the current state
////////////////////////////////////////////////////////////////////////////////
void ServerState::setState(StateEnum state) {
bool result = false;
WRITE_LOCKER(writeLocker, _lock);
if (state == _state) {
return;
}
auto role = getRole();
if (role == ROLE_DBSERVER) {
result = checkPrimaryState(state);
} else if (role == ROLE_COORDINATOR) {
result = checkCoordinatorState(state);
} else if (role == ROLE_SINGLE) {
result = true;
}
if (result) {
LOG_TOPIC("bd5f1", DEBUG, Logger::CLUSTER)
<< "changing state of " << ServerState::roleToString(role)
<< " server from " << ServerState::stateToString(_state) << " to "
<< ServerState::stateToString(state);
_state = state;
} else {
LOG_TOPIC("fb1f9", ERR, Logger::CLUSTER)
<< "invalid state transition for " << ServerState::roleToString(role)
<< " server from " << ServerState::stateToString(_state) << " to "
<< ServerState::stateToString(state);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief gets the JavaScript startup path
////////////////////////////////////////////////////////////////////////////////
std::string ServerState::getJavaScriptPath() {
READ_LOCKER(readLocker, _lock);
return _javaScriptStartupPath;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief sets the arangod path
////////////////////////////////////////////////////////////////////////////////
void ServerState::setJavaScriptPath(std::string const& value) {
WRITE_LOCKER(writeLocker, _lock);
_javaScriptStartupPath = value;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief validate a state transition for a primary server
////////////////////////////////////////////////////////////////////////////////
bool ServerState::checkPrimaryState(StateEnum state) {
if (state == STATE_STARTUP) {
// startup state can only be set once
return (_state == STATE_UNDEFINED);
} else if (state == STATE_SERVING) {
return (_state == STATE_STARTUP || _state == STATE_STOPPED);
} else if (state == STATE_STOPPING) {
return _state == STATE_SERVING;
} else if (state == STATE_STOPPED) {
return (_state == STATE_STOPPING);
} else if (state == STATE_SHUTDOWN) {
return (_state == STATE_STARTUP || _state == STATE_STOPPED || _state == STATE_SERVING);
}
// anything else is invalid
return false;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief validate a state transition for a coordinator server
////////////////////////////////////////////////////////////////////////////////
bool ServerState::checkCoordinatorState(StateEnum state) {
if (state == STATE_STARTUP) {
// startup state can only be set once
return (_state == STATE_UNDEFINED);
} else if (state == STATE_SERVING) {
return (_state == STATE_STARTUP);
} else if (state == STATE_SHUTDOWN) {
return (_state == STATE_STARTUP || _state == STATE_SERVING);
}
// anything else is invalid
return false;
}
bool ServerState::isFoxxmaster() const {
return /*!isRunningInCluster() ||*/ _foxxmaster == getId();
}
std::string const& ServerState::getFoxxmaster() { return _foxxmaster; }
void ServerState::setFoxxmaster(std::string const& foxxmaster) {
if (_foxxmaster != foxxmaster) {
setFoxxmasterQueueupdate(true);
_foxxmaster = foxxmaster;
// We're the new foxxmaster, set this once.
if (isFoxxmaster()) {
setFoxxmasterSinceNow();
}
}
}
bool ServerState::getFoxxmasterQueueupdate() const noexcept {
return _foxxmasterQueueupdate;
}
void ServerState::setFoxxmasterQueueupdate(bool value) {
_foxxmasterQueueupdate = value;
}
TRI_voc_tick_t ServerState::getFoxxmasterSince() const noexcept {
return _foxxmasterSince;
}
void ServerState::setFoxxmasterSinceNow() {
ServerState::_foxxmasterSince = TRI_HybridLogicalClock();
}
std::ostream& operator<<(std::ostream& stream, arangodb::ServerState::RoleEnum role) {
stream << arangodb::ServerState::roleToString(role);
return stream;
}
Result ServerState::propagateClusterReadOnly(bool mode) {
// Agency enabled will work for single server replication as well as cluster
if (AgencyCommManager::isEnabled()) {
std::vector<AgencyOperation> operations;
VPackBuilder builder;
builder.add(VPackValue(mode));
operations.push_back(AgencyOperation("Readonly", AgencyValueOperationType::SET,
builder.slice()));
AgencyWriteTransaction readonlyMode(operations);
AgencyComm comm;
AgencyCommResult r = comm.sendTransactionWithFailover(readonlyMode);
if (!r.successful()) {
return Result(TRI_ERROR_CLUSTER_AGENCY_COMMUNICATION_FAILED, r.errorMessage());
}
// This is propagated to all servers via the heartbeat, which happens
// once per second. So to ensure that every server has taken note of
// the change, we delay here for 2 seconds.
std::this_thread::sleep_for(std::chrono::seconds(2));
}
setReadOnly(mode);
return Result();
}
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