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author | Bernard Gorman <bernard.gorman@gmail.com> | 2019-07-15 11:15:19 +0100 |
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committer | Bernard Gorman <bernard.gorman@gmail.com> | 2019-07-18 22:29:23 +0100 |
commit | ffdb59938db0dfc8ec48e8b74df7a54d07b3a128 (patch) | |
tree | ce0bdfccfb33a8be7aa1a888d9c8199a8dbb6947 /src/mongo/db/pipeline/document_source_check_resume_token.cpp | |
parent | 51a218fb13e02e59afe203c5efd665c9399bfde2 (diff) | |
download | mongo-ffdb59938db0dfc8ec48e8b74df7a54d07b3a128.tar.gz |
SERVER-42232 Adding a new shard renders all preceding resume tokens invalid
Diffstat (limited to 'src/mongo/db/pipeline/document_source_check_resume_token.cpp')
-rw-r--r-- | src/mongo/db/pipeline/document_source_check_resume_token.cpp | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/mongo/db/pipeline/document_source_check_resume_token.cpp b/src/mongo/db/pipeline/document_source_check_resume_token.cpp index 719be15ea2b..5b9eeabaf6c 100644 --- a/src/mongo/db/pipeline/document_source_check_resume_token.cpp +++ b/src/mongo/db/pipeline/document_source_check_resume_token.cpp @@ -331,10 +331,17 @@ void DocumentSourceShardCheckResumability::_assertOplogHasEnoughHistory( auto pipeline = pExpCtx->mongoProcessInterface->makePipeline({matchSpec}, firstEntryExpCtx); if (auto first = pipeline->getNext()) { auto firstOplogEntry = Value(*first); + // If the first entry in the oplog is the replset initialization, then it doesn't matter + // if its timestamp is later than the resume token. No events earlier than the token can + // have fallen off this oplog, and it is therefore safe to resume. Otherwise, verify that + // the timestamp of the first oplog entry is earlier than that of the resume token. + const bool isNewRS = + Value::compare(firstOplogEntry["o"]["msg"], Value("initiating set"_sd), nullptr) == 0 && + Value::compare(firstOplogEntry["op"], Value("n"_sd), nullptr) == 0; uassert(40576, - "Resume of change stream was not possible, as the resume point may no longer " - "be in the oplog. ", - firstOplogEntry["ts"].getTimestamp() < _tokenFromClient.clusterTime); + "Resume of change stream was not possible, as the resume point may no longer be in " + "the oplog. ", + isNewRS || firstOplogEntry["ts"].getTimestamp() < _tokenFromClient.clusterTime); } else { // Very unusual case: the oplog is empty. We can always resume. However, it should never be // possible to have obtained a document that matched the filter if the oplog is empty. |