const st = new ShardingTest({ mongos: [{ setParameter: { logComponentVerbosity: tojson({network: {verbosity: 2}, executor: {verbosity:2}}), // Force the mongos's replica set monitors to always include all the eligible nodes. "failpoint.scanningServerSelectorIgnoreLatencyWindow" : tojson({mode: "alwaysOn" }), "failpoint.sdamServerSelectorIgnoreLatencyWindow" : tojson({mode: "alwaysOn" }), // Force the mongos to send requests to hosts in alphabetical order of host names. "failpoint.networkInterfaceSendRequestsToTargetHostsInAlphabeticalOrder" : tojson({mode: "alwaysOn" }) } }], shards: 1, rs: {nodes: 2, setParameter: {logComponentVerbosity: tojson({command: {verbosity: 2}})}} }); const dbName = "hedged_reads" ; const collName = "test" ; const ns = dbName + "." + collName; const testDB = st.s.getDB(dbName); const numDocs = 10; assert .commandWorked(st.s.adminCommand({enableSharding: dbName})); st.ensurePrimaryShard(dbName, st.shard0.shardName); let bulk = testDB[collName].initializeUnorderedBulkOp(); for (let i = 0; i < numDocs; i++) { bulk.insert({x: i}); } assert .commandWorked(bulk.execute()); assert .commandWorked(st.s.adminCommand({setParameter: 1, maxTimeMSForHedgedReads: 1000})); jsTest.log( "Start test" ); assert .commandWorked(testDB.runCommand({ count: collName, query: {$where: "sleep(100); return true ;" , x: {$gte: 0}}, $readPreference: {mode: "nearest" } })); st.stop(); }()); Logs will show the retry and immediate expiration of hedge read. resmoke.py --suites sharding_auth ./test.js