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  1. Core Server
  2. SERVER-48301

find command should reject $_internalReadAtClusterTime values less than afterClusterTime

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    • Type: Icon: Bug Bug
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 4.7.0
    • Affects Version/s: 4.5.1
    • Component/s: None
    • None
    • Fully Compatible
    • ALL
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      (function() {

let rst = new ReplSetTest({nodes: 1});
rst.startSet();
rst.initiate();

const primary = rst.getPrimary();
const session = primary.startSession({causalConsistency: false});
const db = session.getDatabase('test');
assert.commandWorked(db.test.insert({a: 1}));

let time1 = session.getOperationTime();

assert.commandWorked(db.test.insert({a: 2}));
let time2 = session.getOperationTime();

// Crashes
assert.commandWorked(assert.commandWorked(db.runCommand({
    find: 'test',
    $_internalReadAtClusterTime: time1,
    readConcern: {afterClusterTime: time2},
})));

rst.stopSet();
})();
      Show
      ( function () { let rst = new ReplSetTest({nodes: 1}); rst.startSet(); rst.initiate(); const primary = rst.getPrimary(); const session = primary.startSession({causalConsistency: false }); const db = session.getDatabase( 'test' ); assert.commandWorked(db.test.insert({a: 1})); let time1 = session.getOperationTime(); assert.commandWorked(db.test.insert({a: 2})); let time2 = session.getOperationTime(); // Crashes assert.commandWorked(assert.commandWorked(db.runCommand({ find: 'test' , $_internalReadAtClusterTime: time1, readConcern: {afterClusterTime: time2}, }))); rst.stopSet(); })();
    • Execution Team 2020-06-15
    • 11
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    • 3
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      I added an invariant on the master branch that fails when commands attempt to read at a timestamp that is less than the afterClusterTime readConcern argument, which is contradictory.

      "$_internalReadAtClusterTime" can specify any timestamp and afterClusterTime it wants, easily crashing the server with a simple request.

      We should reject find and getMore commands formed in this way. dbhash does not accept afterClusterTime.

            Assignee:
            louis.williams@mongodb.com Louis Williams
            Reporter:
            louis.williams@mongodb.com Louis Williams
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              Created:
              Updated:
              Resolved: