diff options
Diffstat (limited to 'src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp')
| -rw-r--r-- | src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp | 69 |
1 files changed, 60 insertions, 9 deletions
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp index 8770cac0f0f..8e7f6f80669 100644 --- a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp +++ b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp @@ -113,6 +113,15 @@ bool WiredTigerFileVersion::shouldDowngrade(bool readOnly, return false; } + if (_startupVersion == StartupVersion::IS_42_UPGRADED) { + // Once a 4.4 binary has touched data files, only 4.2.6+ can make sense of them. Note, even + // if the FCV was changed to 4.0, we choose to not make the journal compatible with a 4.0 + // binary. If a primary continues to accept FCV downgrades to 3.6 and earlier, the 4.4 + // touched data files will never be able to recover. At that point, a resync is the only + // option. + return false; + } + const auto replCoord = repl::ReplicationCoordinator::get(getGlobalServiceContext()); const auto memberState = replCoord->getMemberState(); if (memberState.arbiter()) { @@ -155,7 +164,8 @@ bool WiredTigerFileVersion::shouldDowngrade(bool readOnly, std::string WiredTigerFileVersion::getDowngradeString() { if (!serverGlobalParams.featureCompatibility.isVersionInitialized()) { - invariant(_startupVersion != StartupVersion::IS_42); + invariant(_startupVersion != StartupVersion::IS_42_UPGRADED && + _startupVersion != StartupVersion::IS_42_CLASSIC); switch (_startupVersion) { case StartupVersion::IS_34: @@ -668,10 +678,6 @@ WiredTigerKVEngine::WiredTigerKVEngine(const std::string& canonicalName, ss << "verbose=[recovery_progress,checkpoint_progress],"; } - // MongoDB 4.2.6+ will also understand WT compatibility version 3.3. However it should only - // write data in compatibility version 3.2. - ss << "compatibility=(release=3.2,require_max=\"3.3.0\"),"; - // Enable debug write-ahead logging for all tables under debug build. if (kDebugBuild) { ss << "debug_mode=(table_logging=true),"; @@ -817,13 +823,56 @@ void WiredTigerKVEngine::appendGlobalStats(BSONObjBuilder& b) { bb.done(); } +/** + * Table of MongoDB<->WiredTiger<->Log version numbers: + * + * | MongoDB | WiredTiger | Log | + * |------------------------+------------+-----| + * | 3.0.15 | 2.5.3 | 1 | + * | 3.2.20 | 2.9.2 | 1 | + * | 3.4.15 | 2.9.2 | 1 | + * | 3.6.4 | 3.0.1 | 2 | + * | 4.0.16 | 3.1.1 | 3 | + * | 4.2.1 | 3.2.2 | 3 | + * | 4.2.6 | 3.3.0 | 3 | + * | 4.2.6 (blessed by 4.4) | 3.3.0 | 4 | + * | 4.4.0 | 10.0.0 | 5 | + */ void WiredTigerKVEngine::_openWiredTiger(const std::string& path, const std::string& wtOpenConfig) { - std::string configStr = wtOpenConfig + ",compatibility=(require_min=\"3.1.0\")"; + // So long as the data files are never touched by 4.4, MongoDB 4.2.6+ will remain compatible + // with earlier 4.2 versions by using compatibility version 3.2 (log version 3). + // + // Additionally, we first try opening with `release=3.2` to allow fresh "dbpaths" to be + // backwards compatible with earlier 4.2 versions. + std::string configStr = + wtOpenConfig + ",compatibility=(release=3.2,require_min=\"3.2\",require_max=\"3.2\")"; auto wtEventHandler = _eventHandler.getWtEventHandler(); - int ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn); if (!ret) { + _fileVersion = {WiredTigerFileVersion::StartupVersion::IS_42_CLASSIC}; + return; + } + + // If the data files are in 4.4 -> 4.2 downgraded format (log version 4, compatibility version + // 3.3), continue to use compatibility version 3.3. This prevents earlier 4.2 releases from ever + // running on these data files. + configStr = + wtOpenConfig + ",compatibility=(release=3.3,require_min=\"3.3\",require_max=\"3.3\")"; + ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn); + if (!ret) { + _fileVersion = {WiredTigerFileVersion::StartupVersion::IS_42_UPGRADED}; + return; + } + + // This shoud only succeed when the previous datafiles were in compatibility mode + // 3.1. `require_max=` is added for improved WT error messages. "3.3" is used because WT + // disallows using a release outside of the min/max range. These details also apply to the + // remaining `wiredtiger_open` calls. + configStr = + wtOpenConfig + ",compatibility=(release=3.2,require_min=\"3.1\",require_max=\"3.3\")"; + ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn); + if (!ret) { _fileVersion = {WiredTigerFileVersion::StartupVersion::IS_40}; return; } @@ -831,14 +880,16 @@ void WiredTigerKVEngine::_openWiredTiger(const std::string& path, const std::str // Arbiters do not replicate the FCV document. Due to arbiter FCV semantics on 4.0, shutting // down a 4.0 arbiter may either downgrade the data files to WT compatibility 2.9 or 3.0. Thus, // 4.2 binaries must allow starting up on 2.9 and 3.0 files. - configStr = wtOpenConfig + ",compatibility=(require_min=\"3.0.0\")"; + configStr = + wtOpenConfig + ",compatibility=(release=3.2,require_min=\"3.0\",require_max=\"3.3\")"; ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn); if (!ret) { _fileVersion = {WiredTigerFileVersion::StartupVersion::IS_36}; return; } - configStr = wtOpenConfig + ",compatibility=(require_min=\"2.9.0\")"; + configStr = + wtOpenConfig + ",compatibility=(release=3.2,require_min=\"2.9\",require_max=\"3.3\")"; ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn); if (!ret) { _fileVersion = {WiredTigerFileVersion::StartupVersion::IS_34}; |