给您的 MongoDB 定期做个体检:MongoDB 诊断
新钛云服已累计为您分享739篇技术干货
接下来的一些列文章会为大家介绍日常工作中常用的 NoSQL 产品 MongoDB。
主要涉及到:
MongoDB 的安装及基本使用
MongoDB 文档查询
MongoDB 复制集
MongoDB 分片集群的介绍及搭建
MongoDB 安全加密
MongoDB 诊断
我们会用六篇文章近五万字来阐述 MongoDB 运维相关的日常实战事宜。您当前看到的是系列文章的第六篇:《MongoDB 诊断》。
随着 MongoDB 的不断运行且数据量日益增多,就会不免产生一些问题。当问题出现时,该怎么办呢?我们会从以下几个方面进行探讨。
日志
当有个长期运行的 MongoDB 进程时,我们可能想自己写个脚本来定期轮转日志文件。其实不用,MongoDB 已经提供了 logrotate
命令来完成这个操作,可以直接从 shell 里启动使用:
use adminrs0:PRIMARY> db.runCommand({logRotate: 1})
{"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1679966896, 1),"signature" : {"hash" : BinData(0,"50vWhFp/59fAKwBbUQUDxApF/+g="),"keyId" : NumberLong("7173500260914823169")}},"operationTime" : Timestamp(1679966896, 1)
}
需要注意:logRotate 是区分大小写的。
或者可以向 Mongo 进程发送 SIGUSR1
信号:
$ kill -SIGUSR1 <mongo_pid>
诊断命令
MongoDB 包含了许多命令可以报告内部状态,这些命令背后都是监控 MongoDB。下面是一些常见命令的参考命令,希望对大家有所帮助:
全局服务器统计信息:
db.serverStatus();
统计当前运行的操作:
db.currentOp();
包含空闲的操作:
db currentOp(true)
每个数据库的计数器和活动统计:
db.runCommand({top: 1}) ;
查看当前数据库信息:
db.stats()
我们接下来分别看一看上述这几个命令的输出。
01
全局服务器信息统计
该命令输出的信息非常详细,当 MongoDB 出现问题时,是一个不错的诊断命令。
rs0:PRIMARY> db.serverStatus()
{"host" : "mongo03.tyun.cn","version" : "4.4.15","process" : "mongod","pid" : NumberLong(14092),"uptime" : 18727504,"uptimeMillis" : NumberLong("18727504137"),"uptimeEstimate" : NumberLong(18727504),"localTime" : ISODate("2023-03-28T01:30:35.805Z"),"asserts" : {"regular" : 0,"warning" : 0,"msg" : 0,"user" : 1380727,"rollovers" : 0},"connections" : {"current" : 17,"available" : 51183,"totalCreated" : 3253,"active" : 7,"exhaustIsMaster" : 3,"exhaustHello" : 2,"awaitingTopologyChanges" : 176},"defaultRWConcern" : {"localUpdateWallClockTime" : ISODate("2022-08-23T07:25:32.995Z")},"tcmalloc" : {"pageheap_free_bytes" : 94162944,"pageheap_unmapped_bytes" : 349478912,"max_total_thread_cache_bytes" : 1024458752,"current_total_thread_cache_bytes" : 238198560,"total_free_bytes" : 637257904,"central_cache_free_bytes" : 397502736,"transfer_cache_free_bytes" : 1556608,"thread_cache_free_bytes" : 238198560,"aggressive_memory_decommit" : 0,"pageheap_committed_bytes" : NumberLong("3653197824"),"pageheap_scavenge_count" : 13297522,"pageheap_commit_count" : 14804116,"pageheap_total_commit_bytes" : NumberLong("60304102580224"),"pageheap_decommit_count" : 13297522,"pageheap_total_decommit_bytes" : NumberLong("60300449382400"),"pageheap_reserve_count" : 459,"pageheap_total_reserve_bytes" : NumberLong("4002676736"),"spinlock_total_delay_ns" : NumberLong("111430768421"),"release_rate" : 1,"formattedString" : "------------------------------------------------\nMALLOC: 2921777552 ( 2786.4 MiB) Bytes in use by application\nMALLOC: + 94162944 ( 89.8 MiB) Bytes in page heap freelist\nMALLOC: + 397502736 ( 379.1 MiB) Bytes in central cache freelist\nMALLOC: + 1556608 ( 1.5 MiB) Bytes in transfer cache freelist\nMALLOC: + 238197984 ( 227.2 MiB) Bytes in thread cache freelists\nMALLOC: + 24510464 ( 23.4 MiB) Bytes in malloc metadata\nMALLOC: ------------\nMALLOC: = 3677708288 ( 3507.3 MiB) Actual memory used (physical + swap)\nMALLOC: + 349478912 ( 333.3 MiB) Bytes released to OS (aka unmapped)\nMALLOC: ------------\nMALLOC: = 4027187200 ( 3840.6 MiB) Virtual address space used\nMALLOC:\nMALLOC: 265177 Spans in use\nMALLOC: 72 Thread heaps in use\nMALLOC: 4096 Tcmalloc page size\n------------------------------------------------\nCall ReleaseFreeMemory() to release freelist memory to the OS (via madvise()).\nBytes released to the OS take up virtual address space but no physical memory.\n"}},"trafficRecording" : {"running" : false},"transactions" : {"retriedCommandsCount" : NumberLong(0),"retriedStatementsCount" : NumberLong(0),"transactionsCollectionWriteCount" : NumberLong(0),"currentActive" : NumberLong(0),"currentInactive" : NumberLong(0),"currentOpen" : NumberLong(0),"totalAborted" : NumberLong(0),"totalCommitted" : NumberLong(0),"totalStarted" : NumberLong(0),"totalPrepared" : NumberLong(0),"totalPreparedThenCommitted" : NumberLong(0),"totalPreparedThenAborted" : NumberLong(0),"currentPrepared" : NumberLong(0)},"transportSecurity" : {"1.0" : NumberLong(0),"1.1" : NumberLong(0),"1.2" : NumberLong(0),"1.3" : NumberLong(0),"unknown" : NumberLong(0)},"twoPhaseCommitCoordinator" : {"totalCreated" : NumberLong(0),"totalStartedTwoPhaseCommit" : NumberLong(0),"totalAbortedTwoPhaseCommit" : NumberLong(0),"totalCommittedTwoPhaseCommit" : NumberLong(0),"currentInSteps" : {"writingParticipantList" : NumberLong(0),"waitingForVotes" : NumberLong(0),"writingDecision" : NumberLong(0),"waitingForDecisionAcks" : NumberLong(0),"deletingCoordinatorDoc" : NumberLong(0)}},"wiredTiger" : {"uri" : "statistics:","block-manager" : {"blocks pre-loaded" : 23,"blocks read" : 4268362,"blocks written" : 39421996,"bytes read" : 48401854464,"bytes read via memory map API" : 0,"bytes read via system call API" : 0,"bytes written" : 418967826432,"bytes written for checkpoint" : 305570754560,"bytes written via memory map API" : 0,"bytes written via system call API" : 0,"mapped blocks read" : 0,"mapped bytes read" : 0,"number of times the file was remapped because it changed size via fallocate or truncate" : 0,"number of times the region was remapped via write" : 0},"capacity" : {"background fsync file handles considered" : 0,"background fsync file handles synced" : 0,"background fsync time (msecs)" : 0,"bytes read" : 39614959616,"bytes written for checkpoint" : 239185165378,"bytes written for eviction" : 97795992160,"bytes written for log" : 157233860864,"bytes written total" : 494215018402,"threshold to call fsync" : 0,"time waiting due to total capacity (usecs)" : 0,"time waiting during checkpoint (usecs)" : 0,"time waiting during eviction (usecs)" : 0,"time waiting during logging (usecs)" : 0,"time waiting during read (usecs)" : 0},"checkpoint-cleanup" : {"pages added for eviction" : 81667,"pages removed" : 16946,"pages skipped during tree walk" : 3064011324,"pages visited" : 5381579176},"connection" : {"auto adjusting condition resets" : 6326104,"auto adjusting condition wait calls" : 121447994,"auto adjusting condition wait raced to update timeout and skipped updating" : 61,"detected system time went backwards" : 0,"files currently open" : 71,"hash bucket array size for data handles" : 512,"hash bucket array size general" : 512,"memory allocations" : 14030754494,"memory frees" : 14027269174,"memory re-allocations" : 161883962,"pthread mutex condition wait calls" : 314479507,"pthread mutex shared lock read-lock calls" : 12181240198,"pthread mutex shared lock write-lock calls" : 743154980,"total fsync I/Os" : 275579938,"total read I/Os" : 4582332,"total write I/Os" : 313739357},"mem" : {"bits" : 64,"resident" : 3423,"virtual" : 5564,"supported" : true},"metrics" : {"aggStageCounters" : {"$_internalInhibitOptimization" : NumberLong(0),"$_internalSplitPipeline" : NumberLong(0),"$addFields" : NumberLong(1),"$bucket" : NumberLong(0),"$bucketAuto" : NumberLong(0),"$changeStream" : NumberLong(0),"$collStats" : NumberLong(0),"$count" : NumberLong(0),"$currentOp" : NumberLong(0),"$documents" : NumberLong(0),"$facet" : NumberLong(0),"$geoNear" : NumberLong(0),"$graphLookup" : NumberLong(0),"$group" : NumberLong(0),"$indexStats" : NumberLong(0),"$limit" : NumberLong(0),"$listLocalSessions" : NumberLong(0),"$listSessions" : NumberLong(0),"$lookup" : NumberLong(0),"$match" : NumberLong(1),"$merge" : NumberLong(0),"$mergeCursors" : NumberLong(0),"$out" : NumberLong(0),"$planCacheStats" : NumberLong(0),"$project" : NumberLong(2),"$queue" : NumberLong(0),"$redact" : NumberLong(0),"$replaceRoot" : NumberLong(0),"$replaceWith" : NumberLong(0),"$sample" : NumberLong(0),"$set" : NumberLong(46126),"$skip" : NumberLong(0),"$sort" : NumberLong(1),"$sortByCount" : NumberLong(0),"$unionWith" : NumberLong(0),"$unset" : NumberLong(0),"$unwind" : NumberLong(0)},"commands" : {"<UNKNOWN>" : NumberLong(2),"_isSelf" : {"failed" : NumberLong(0),"total" : NumberLong(13)},"buildInfo" : {"failed" : NumberLong(0),"total" : NumberLong(690365)},"count" : {"failed" : NumberLong(0),"total" : NumberLong(6)},"delete" : {"failed" : NumberLong(0),"total" : NumberLong(48)},"endSessions" : {"failed" : NumberLong(0),"total" : NumberLong(134)},"find" : {"failed" : NumberLong(0),"total" : NumberLong(2142077)},"getCmdLineOpts" : {"failed" : NumberLong(0),"total" : NumberLong(1380235)},"getDiagnosticData" : {"failed" : NumberLong(0),"total" : NumberLong(2070345)},"getFreeMonitoringStatus" : {"failed" : NumberLong(0),"total" : NumberLong(5)},"getLastError" : {"failed" : NumberLong(0),"total" : NumberLong(101)},"getLog" : {"failed" : NumberLong(0),"total" : NumberLong(5)},"getMore" : {"failed" : NumberLong(1),"total" : NumberLong(465344562)},"getnonce" : {"failed" : NumberLong(0),"total" : NumberLong(2)},"hello" : {"failed" : NumberLong(268),"total" : NumberLong(1384888)},"insert" : {"failed" : NumberLong(0),"total" : NumberLong(1)},"isMaster" : {"failed" : NumberLong(2),"total" : NumberLong(7731521)},"killCursors" : {"failed" : NumberLong(0),"total" : NumberLong(5)},"listCollections" : {"failed" : NumberLong(0),"total" : NumberLong(10)},"listDatabases" : {"failed" : NumberLong(0),"total" : NumberLong(57515)},"listIndexes" : {"failed" : NumberLong(3),"total" : NumberLong(124851)},"logRotate" : {"failed" : NumberLong(0),"total" : NumberLong(1)},"ping" : {"failed" : NumberLong(0),"total" : NumberLong(4436308)},"replSetGetConfig" : {"failed" : NumberLong(0),"total" : NumberLong(2070345)},"replSetGetRBID" : {"failed" : NumberLong(0),"total" : NumberLong(6)},"replSetGetStatus" : {"failed" : NumberLong(0),"total" : NumberLong(690128)},"replSetHeartbeat" : {"failed" : NumberLong(0),"total" : NumberLong(17000850)},"replSetRequestVotes" : {"failed" : NumberLong(0),"total" : NumberLong(4)},"replSetUpdatePosition" : {"failed" : NumberLong(0),"total" : NumberLong(390211482)},"rolesInfo" : {"failed" : NumberLong(0),"total" : NumberLong(1)},"saslContinue" : {"failed" : NumberLong(6),"total" : NumberLong(62466)},"saslStart" : {"failed" : NumberLong(0),"total" : NumberLong(57875)},"serverStatus" : {"failed" : NumberLong(0),"total" : NumberLong(1)},"update" : {"arrayFilters" : NumberLong(0),"failed" : NumberLong(0),"pipeline" : NumberLong(23063),"total" : NumberLong(511271)},"usersInfo" : {"failed" : NumberLong(0),"total" : NumberLong(1)},"whatsmyuri" : {"failed" : NumberLong(0),"total" : NumberLong(5)}},"cursor" : {"timedOut" : NumberLong(0),"open" : {"noTimeout" : NumberLong(0),"pinned" : NumberLong(1),"total" : NumberLong(1)}},"document" : {"deleted" : NumberLong(0),"inserted" : NumberLong(1),"returned" : NumberLong(322743825),"updated" : NumberLong(522796)},"getLastError" : {"wtime" : {"num" : 11577,"totalMillis" : 37265},"wtimeouts" : NumberLong(1),"default" : {"unsatisfiable" : NumberLong(0),"wtimeouts" : NumberLong(0)}},"operation" : {"scanAndOrder" : NumberLong(15),"writeConflicts" : NumberLong(9825)},"query" : {"planCacheTotalSizeEstimateBytes" : NumberLong(0),"updateOneOpStyleBroadcastWithExactIDCount" : NumberLong(0),"multiPlanner" : {"classicCount" : NumberLong(0),"classicMicros" : NumberLong(0),"classicWorks" : NumberLong(0),"histograms" : {"classicMicros" : [{"lowerBound" : NumberLong(0),"count" : NumberLong(0)},{"lowerBound" : NumberLong(1024),"count" : NumberLong(0)},{"lowerBound" : NumberLong(4096),"count" : NumberLong(0)},{"lowerBound" : NumberLong(16384),"count" : NumberLong(0)},{"lowerBound" : NumberLong(65536),"count" : NumberLong(0)},{"lowerBound" : NumberLong(262144),"count" : NumberLong(0)},{"lowerBound" : NumberLong(1048576),"count" : NumberLong(0)},{"lowerBound" : NumberLong(4194304),"count" : NumberLong(0)},{"lowerBound" : NumberLong(16777216),"count" : NumberLong(0)},{"lowerBound" : NumberLong(67108864),"count" : NumberLong(0)},{"lowerBound" : NumberLong(268435456),"count" : NumberLong(0)},{"lowerBound" : NumberLong(1073741824),"count" : NumberLong(0)}],"classicNumPlans" : [{"lowerBound" : NumberLong(0),"count" : NumberLong(0)},{"lowerBound" : NumberLong(2),"count" : NumberLong(0)},{"lowerBound" : NumberLong(4),"count" : NumberLong(0)},{"lowerBound" : NumberLong(8),"count" : NumberLong(0)},{"lowerBound" : NumberLong(16),"count" : NumberLong(0)},{"lowerBound" : NumberLong(32),"count" : NumberLong(0)}],"classicWorks" : [{"lowerBound" : NumberLong(0),"count" : NumberLong(0)},{"lowerBound" : NumberLong(128),"count" : NumberLong(0)},{"lowerBound" : NumberLong(256),"count" : NumberLong(0)},{"lowerBound" : NumberLong(512),"count" : NumberLong(0)},{"lowerBound" : NumberLong(1024),"count" : NumberLong(0)},{"lowerBound" : NumberLong(2048),"count" : NumberLong(0)},{"lowerBound" : NumberLong(4096),"count" : NumberLong(0)},{"lowerBound" : NumberLong(8192),"count" : NumberLong(0)},{"lowerBound" : NumberLong(16384),"count" : NumberLong(0)},{"lowerBound" : NumberLong(32768),"count" : NumberLong(0)}]}}},"queryExecutor" : {"scanned" : NumberLong(1070392),"scannedObjects" : NumberLong(323266658),"collectionScans" : {"nonTailable" : NumberLong(1386454),"total" : NumberLong(1386461)}},"record" : {"moves" : NumberLong(0)},"repl" : {"executor" : {"pool" : {"inProgressCount" : 0},"queues" : {"networkInProgress" : 0,"sleepers" : 3},"unsignaledEvents" : 0,"shuttingDown" : false,"networkInterface" : "DEPRECATED: getDiagnosticString is deprecated in NetworkInterfaceTL"},"apply" : {"attemptsToBecomeSecondary" : NumberLong(19),"batchSize" : NumberLong(318318346),"batches" : {"num" : 278600198,"totalMillis" : 5795319},"ops" : NumberLong(318318943)},"buffer" : {"count" : NumberLong(0),"maxSizeBytes" : NumberLong(268435456),"sizeBytes" : NumberLong(0)},"initialSync" : {"completed" : NumberLong(0),"failedAttempts" : NumberLong(0),"failures" : NumberLong(0)},"network" : {"bytes" : NumberLong("57955381887"),"getmores" : {"num" : 364468339,"totalMillis" : 15110995960,"numEmptyBatches" : NumberLong(67943454)},"notPrimaryLegacyUnacknowledgedWrites" : NumberLong(0),"notPrimaryUnacknowledgedWrites" : NumberLong(0),"oplogGetMoresProcessed" : {"num" : 465344548,"totalMillis" : 200161},"ops" : NumberLong(318318349),"readersCreated" : NumberLong(5),"replSetUpdatePosition" : {"num" : NumberLong(455260555)}},"stateTransition" : {"lastStateTransition" : "stepUp","userOperationsKilled" : NumberLong(0),"userOperationsRunning" : NumberLong(5)},"syncSource" : {"numSelections" : NumberLong(28),"numTimesChoseDifferent" : NumberLong(3),"numTimesChoseSame" : NumberLong(0),"numTimesCouldNotFind" : NumberLong(25)}},"ttl" : {"deletedDocuments" : NumberLong(9),"passes" : NumberLong(312121)}},"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1679967033, 3),"signature" : {"hash" : BinData(0,"7p9I6mnYmAqWdGWHZuVRCfEIJtU="),"keyId" : NumberLong("7173500260914823169")}},"operationTime" : Timestamp(1679967033, 3)
}
02
统计当前运行的操作
rs0:PRIMARY> db.currentOp()
{"inprog" : [{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "OplogApplier-0","active" : true,"currentOpTime" : "2023-03-28T01:37:05.539+00:00","effectiveUsers" : [{"user" : "__system","db" : "local"}],"opid" : -935445419,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "TimestampMonitor","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445412,"op" : "none","ns" : "","command" : {},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:37:05.546Z"),"captureName" : "ServiceContext::_mutex"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "ReplBatcher","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445421,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {"FeatureCompatibilityVersion" : {"acquireCount" : {"r" : NumberLong(1)}},"ReplicationStateTransition" : {"acquireCount" : {"w" : NumberLong(1)}},"Global" : {"acquireCount" : {"r" : NumberLong(1)}}},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn333","connectionId" : 333,"client" : "10.20.20.11:42734","clientMetadata" : {"driver" : {"name" : "NetworkInterfaceTL","version" : "4.4.15"},"os" : {"type" : "Linux","name" : "CentOS Linux release 7.9.2009 (Core)","architecture" : "x86_64","version" : "Kernel 3.10.0-1160.62.1.el7.x86_64"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","effectiveUsers" : [{"user" : "__system","db" : "local"}],"opid" : -935445430,"secs_running" : NumberLong(1),"microsecs_running" : NumberLong(1002908),"op" : "command","ns" : "admin.$cmd","command" : {"isMaster" : 1,"maxAwaitTimeMS" : NumberLong(10000),"topologyVersion" : {"processId" : ObjectId("630480eb8e13bda8cb16c7e9"),"counter" : NumberLong(28)},"internalClient" : {"minWireVersion" : 9,"maxWireVersion" : 9},"$db" : "admin"},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:37:04.649Z"),"captureName" : "FutureResolution"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn6901","connectionId" : 6901,"client" : "10.20.20.19:56616","appName" : "MongoDB Shell","clientMetadata" : {"application" : {"name" : "MongoDB Shell"},"driver" : {"name" : "MongoDB Internal Client","version" : "4.4.15"},"os" : {"type" : "Linux","name" : "CentOS Linux release 7.9.2009 (Core)","architecture" : "x86_64","version" : "Kernel 3.10.0-1160.62.1.el7.x86_64"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","effectiveUsers" : [{"user" : "root","db" : "admin"}],"opid" : -935445413,"lsid" : {"id" : UUID("5daca131-7d85-4e21-a44b-2b1ded973009"),"uid" : BinData(0,"Y5mrDaxi8gv8RmdTsQ+1j7fmkr7JUsabhNmXAheU0fg=")},"secs_running" : NumberLong(0),"microsecs_running" : NumberLong(22989),"op" : "command","ns" : "admin.$cmd.aggregate","command" : {"currentOp" : 1,"lsid" : {"id" : UUID("5daca131-7d85-4e21-a44b-2b1ded973009")},"$clusterTime" : {"clusterTime" : Timestamp(1679967416, 1),"signature" : {"hash" : BinData(0,"hZEpDTiaiD3Zna+djn4cNU7WLjE="),"keyId" : NumberLong("7173500260914823169")}},"$db" : "admin"},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "OplogCapMaintainerThread-local.oplog.rs","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -964016203,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {"FeatureCompatibilityVersion" : {"acquireCount" : {"w" : NumberLong(1)}},"ReplicationStateTransition" : {"acquireCount" : {"w" : NumberLong(1)}},"Global" : {"acquireCount" : {"w" : NumberLong(1)}}},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn2762","connectionId" : 2762,"client" : "10.20.20.41:33548","appName" : "QAN-mongodb-profiler-/agent_id/549d2b38-caf8-44a4-9903-28f769a12e68","clientMetadata" : {"driver" : {"name" : "mongo-go-driver","version" : "v1.11.1"},"os" : {"type" : "linux","architecture" : "amd64"},"platform" : "go1.19.1","application" : {"name" : "QAN-mongodb-profiler-/agent_id/549d2b38-caf8-44a4-9903-28f769a12e68"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445550,"secs_running" : NumberLong(7),"microsecs_running" : NumberLong(7041972),"op" : "command","ns" : "admin.$cmd","command" : {"hello" : 1,"helloOk" : true,"topologyVersion" : {"processId" : ObjectId("630480eb8e13bda8cb16c7e9"),"counter" : NumberLong(28)},"maxAwaitTimeMS" : NumberLong(10000),"$db" : "admin","$readPreference" : {"mode" : "primaryPreferred"}},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:36:58.610Z"),"captureName" : "FutureResolution"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "JournalFlusher","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445414,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn332","connectionId" : 332,"client" : "10.20.20.11:42736","clientMetadata" : {"driver" : {"name" : "NetworkInterfaceTL","version" : "4.4.15"},"os" : {"type" : "Linux","name" : "CentOS Linux release 7.9.2009 (Core)","architecture" : "x86_64","version" : "Kernel 3.10.0-1160.62.1.el7.x86_64"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","effectiveUsers" : [{"user" : "__system","db" : "local"}],"opid" : -935445538,"secs_running" : NumberLong(6),"microsecs_running" : NumberLong(6388394),"op" : "command","ns" : "admin.$cmd","command" : {"isMaster" : 1,"maxAwaitTimeMS" : NumberLong(10000),"topologyVersion" : {"processId" : ObjectId("630480eb8e13bda8cb16c7e9"),"counter" : NumberLong(28)},"internalClient" : {"minWireVersion" : 9,"maxWireVersion" : 9},"$db" : "admin"},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:36:59.264Z"),"captureName" : "FutureResolution"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "NoopWriter","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445599,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn326","connectionId" : 326,"client" : "10.20.20.11:42726","appName" : "OplogFetcher","clientMetadata" : {"application" : {"name" : "OplogFetcher"},"driver" : {"name" : "MongoDB Internal Client","version" : "4.4.15"},"os" : {"type" : "Linux","name" : "CentOS Linux release 7.9.2009 (Core)","architecture" : "x86_64","version" : "Kernel 3.10.0-1160.62.1.el7.x86_64"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","effectiveUsers" : [{"user" : "__system","db" : "local"}],"opid" : -935445493,"secs_running" : NumberLong(3),"microsecs_running" : NumberLong(3702937),"op" : "getmore","ns" : "local.oplog.rs","command" : {"getMore" : NumberLong("3869305470684881343"),"collection" : "oplog.rs","batchSize" : NumberLong(13981010),"maxTimeMS" : NumberLong(5000),"term" : NumberLong(3),"lastKnownCommittedOpTime" : {"ts" : Timestamp(1661570687, 1397),"t" : NumberLong(2)},"$db" : "local","$replData" : 1,"$oplogQueryData" : 1,"$readPreference" : {"mode" : "secondaryPreferred"},"$clusterTime" : {"clusterTime" : Timestamp(1661570687, 1399),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}}},"planSummary" : "COLLSCAN",{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn2764","connectionId" : 2764,"client" : "10.20.20.41:33552","appName" : "mongodb_exporter","clientMetadata" : {"driver" : {"name" : "mongo-go-driver","version" : "v1.10.3"},"os" : {"type" : "linux","architecture" : "amd64"},"platform" : "go1.19.1","application" : {"name" : "mongodb_exporter"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445535,"secs_running" : NumberLong(6),"microsecs_running" : NumberLong(6117158),"op" : "command","ns" : "admin.$cmd","command" : {"hello" : 1,"helloOk" : true,"topologyVersion" : {"processId" : ObjectId("630480eb8e13bda8cb16c7e9"),"counter" : NumberLong(28)},"maxAwaitTimeMS" : NumberLong(10000),"$db" : "admin","$readPreference" : {"mode" : "primaryPreferred"}},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:36:59.535Z"),"captureName" : "FutureResolution"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "WTCheckpointThread","active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","opid" : -935445426,"op" : "none","ns" : "","command" : {},"numYields" : 0,"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}},{"type" : "op","host" : "mongo03.tyun.cn:27017","desc" : "conn184","connectionId" : 184,"client" : "10.20.20.41:45032","clientMetadata" : {"driver" : {"name" : "NetworkInterfaceTL","version" : "4.4.15"},"os" : {"type" : "Linux","name" : "CentOS Linux release 7.9.2009 (Core)","architecture" : "x86_64","version" : "Kernel 3.10.0-1160.62.1.el7.x86_64"}},"active" : true,"currentOpTime" : "2023-03-28T01:37:05.552+00:00","effectiveUsers" : [{"user" : "__system","db" : "local"}],"opid" : -935445564,"secs_running" : NumberLong(7),"microsecs_running" : NumberLong(7951531),"op" : "command","ns" : "admin.$cmd","command" : {"isMaster" : 1,"maxAwaitTimeMS" : NumberLong(10000),"topologyVersion" : {"processId" : ObjectId("630480eb8e13bda8cb16c7e9"),"counter" : NumberLong(28)},"internalClient" : {"minWireVersion" : 9,"maxWireVersion" : 9},"$db" : "admin"},"numYields" : 0,"waitingForLatch" : {"timestamp" : ISODate("2023-03-28T01:36:57.701Z"),"captureName" : "FutureResolution"},"locks" : {},"waitingForLock" : false,"lockStats" : {},"waitingForFlowControl" : false,"flowControlStats" : {}}],"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1679967416, 1),"signature" : {"hash" : BinData(0,"hZEpDTiaiD3Zna+djn4cNU7WLjE="),"keyId" : NumberLong("7173500260914823169")}},"operationTime" : Timestamp(1679967416, 1)
}
03
查看当前数据库统计信息
该命令返回当前连接的数据库信息。如:查看 admin 数据库信息:
rs0:PRIMARY> db.stats()
{"db" : "admin","collections" : 4,"views" : 0,"objects" : 10,"avgObjSize" : 242.8,"dataSize" : 2428,"storageSize" : 131072,"indexes" : 6,"indexSize" : 188416,"totalSize" : 319488,"scaleFactor" : 1,"fsUsedSize" : 44225654784,"fsTotalSize" : 64174051328,"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1679967646, 1),"signature" : {"hash" : BinData(0,"G/+ynHN7GNtj09WoJaJ4TMXR/sc="),"keyId" : NumberLong("7173500260914823169")}},"operationTime" : Timestamp(1679967646, 1)
}
还可以查看其他数据库信息:
rs0:PRIMARY> show dbs
admin 0.000GB
config 0.000GB
local 3.794GB
mongoshake 0.000GB
signals 0.000GB
streams 0.000GB
test 6.814GB
ycsb 14.253GB
rs0:PRIMARY> use streams
switched to db streams
rs0:PRIMARY> db.stats()
{"db" : "streams","collections" : 2,"views" : 0,"objects" : 2,"avgObjSize" : 40,"dataSize" : 80,"storageSize" : 40960,"indexes" : 2,"indexSize" : 40960,"totalSize" : 81920,"scaleFactor" : 1,"fsUsedSize" : 44226154496,"fsTotalSize" : 64174051328,"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1679967836, 1),"signature" : {"hash" : BinData(0,"L0keGbNUzAlINUX7sbG9t2TzkAk="),"keyId" : NumberLong("7173500260914823169")}},"operationTime" : Timestamp(1679967836, 1)
}
04
mongostat
mongostat 是 db.currentOp()
及 db.serverStatus()
命令的外部工具。以下是一个演示:
[root@mongo01 ~]# mongostat --host mongo03.tyun.cn:27017 --authenticationDatabase admin -u root 5
Enter password:insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn set repl time*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.61k 56.7k 19 rs0 PRI Mar 28 01:46:02.077*0 *0 *0 *0 0 4|0 0.3% 78.8% 1 5.43G 3.34G 0|0 1|0 1.78k 56.7k 19 rs0 PRI Mar 28 01:46:07.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.61k 56.8k 19 rs0 PRI Mar 28 01:46:12.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.79k 56.6k 19 rs0 PRI Mar 28 01:46:17.075*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:46:22.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:46:27.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:46:32.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:46:37.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:46:42.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:46:47.074
insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn set repl time*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:46:52.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:46:57.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:02.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 1 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:47:07.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:12.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.79k 56.6k 19 rs0 PRI Mar 28 01:47:17.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:22.076*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:47:27.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:32.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:47:37.074
insert query update delete getmore command dirty used flushes vsize res qrw arw net_in net_out conn set repl time*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:42.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:47:47.073*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:47:52.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:47:57.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:48:02.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 1 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:48:07.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:48:12.074*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.79k 56.6k 19 rs0 PRI Mar 28 01:48:17.074*0 *0 *0 *0 0 5|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.65k 56.9k 19 rs0 PRI Mar 28 01:48:22.075*0 *0 *0 *0 0 4|0 0.3% 78.8% 0 5.43G 3.34G 0|0 1|0 1.74k 56.5k 19 rs0 PRI Mar 28 01:48:27.074
05
mongotop
mongotop 是 db.runCommand({top: 1})
命令的外部工具。以下是命令的演示:
[root@mongo01 ~]# mongotop --host mongo03.tyun.cn:27017 --authenticationDatabase admin -u root 5
Enter password:2023-03-28T01:50:12.279+0000 connected to: mongodb://mongo03.tyun.cn:27017/ns total read write 2023-03-28T01:50:17Zlocal.oplog.rs 4ms 4ms 0ms admin.$cmd.aggregate 0ms 0ms 0ms admin.system.keys 0ms 0ms 0ms admin.system.profile 0ms 0ms 0ms admin.system.roles 0ms 0ms 0ms admin.system.users 0ms 0ms 0ms admin.system.version 0ms 0ms 0ms config.settings 0ms 0ms 0ms
config.system.indexBuilds 0ms 0ms 0ms config.system.profile 0ms 0ms 0ms ns total read write 2023-03-28T01:50:22Zlocal.oplog.rs 4ms 4ms 0ms admin.$cmd.aggregate 0ms 0ms 0ms admin.system.keys 0ms 0ms 0ms admin.system.profile 0ms 0ms 0ms admin.system.roles 0ms 0ms 0ms admin.system.users 0ms 0ms 0ms admin.system.version 0ms 0ms 0ms config.settings 0ms 0ms 0ms
config.system.indexBuilds 0ms 0ms 0ms config.system.profile 0ms 0ms 0ms ns total read write 2023-03-28T01:50:27Zlocal.oplog.rs 4ms 4ms 0ms admin.$cmd.aggregate 0ms 0ms 0ms admin.system.keys 0ms 0ms 0ms admin.system.profile 0ms 0ms 0ms admin.system.roles 0ms 0ms 0ms admin.system.users 0ms 0ms 0ms admin.system.version 0ms 0ms 0ms config.settings 0ms 0ms 0ms
config.system.indexBuilds 0ms 0ms 0ms config.system.profile 0ms 0ms 0ms ^C2023-03-28T01:50:28.048+0000 signal 'interrupt' received; forcefully terminating
监控
监控是少不了的,可以考虑从主机及服务监控两个方面来监控 MongoDB。
01
主机监控
MongoDB 所在主机的监控是不可缺少的。现在有很多成熟的监控工具,具体选用什么监控工具,可以按照自己的习惯来选择即可。
02
服务监控
服务监控更是不可缺少的。
另外,我们对某个实例进行压测时,看看服务可以承受多大的压力,具体瓶颈在哪里,通过监控趋势图可以看得一清二楚。如:
./bin/ycsb run mongodb -s \-P workloads/workloada \-p recordcount=1000000 -p operationcount=1000000 \-p readproportion=0.5 -p updateproportion=0.5 \-p requestdistribution=zipfian \-p mongodb.url="mongodb://root:root123@mongo03.tyun.cn:27017/admin?waitQueueMultiple=100" \-threads 500
在对数据库进行压测时,可以查看监控:
总结
上面我们介绍了一些列的诊断工具,可以帮助我们迅速地判断当前 MongoDB 的运行状态。通过这些诊断,就可以给 MongoDB 开出一个药方,使其更健康。
本系列文章到此结束,希望本系列文章对大家有所帮助。后续我们会有更多的话题,请大家继续关注。
推荐阅读
推荐视频
相关文章:

给您的 MongoDB 定期做个体检:MongoDB 诊断
新钛云服已累计为您分享739篇技术干货接下来的一些列文章会为大家介绍日常工作中常用的 NoSQL 产品 MongoDB。主要涉及到:MongoDB 的安装及基本使用 MongoDB 文档查询 MongoDB 复制集 MongoDB 分片集群的介绍及搭建 MongoDB 安全加密 MongoDB 诊断我们会用…...

【云原生进阶之容器】第五章容器运行时5.8--容器热迁移
《云原生进阶之容器》专题索引: 第一章Docker核心技术1.1节——Docker综述第一章Docker核心技术1.2节——Linux容器LXC第一章Docker核心技术1.3节——命名空间Namespace第一章Docker核心技术1.4节——chroot技术第一章Docker核心技术1.5.1节——cgroup综述...
react框架的简单认识
React框架 众所周知,React与Vue,Angular被前端开发人员称为前端的三大框架。在如今,React和Vue相对于老牌的Angular,它们的表现更为出色,常常被各大公司使用。但其中React的技术难度要稍稍大于Vue,不过为了…...

IDEA的基本使用
IDEA的基本使用IDEA的基本使用1 IDEA概述2 IDEA的下载和安装2.1 下载2.2 安装3 IDEA中层级结构介绍3.1 结构分类3.2 结构介绍project(项目、工程)module(模块)package(包)class(类)3…...
【MySQL】实验八 触发器与存储过程
文章目录 1. 创建商品价格修改记录表2. 创建触发器,当更改商品价格(price列)时,记录价格3. SQL触发器:插入新员工时,同步更新部门表相应人数4. SQL触发器:删除学生数据5. SQL触发器:创建成绩表插入触发器6. SQL存储过程:查询订单7. SQL存储过程:建立存储过程,查询课程…...
Mockito5.2.0学习
Mockito是mocking框架,它让你用简洁的API做测试。而且Mockito简单易学,它可读性强和验证语法简洁。 Mockito 是一个针对 Java 的单元测试模拟框架,它与 EasyMock 和 jMock 很相似,都是为了简化单元测试过程中测试上下文 ( 或者称之…...
用指针实现内存动态分配
导引:已知:变量在使用前必须被定义且安排好存储空间。且变量有这么一些分类:全局变量、静态局部变量【它们的储存一般是在编译时确定,在程序开始执行前完成。】自动变量【在执行进入变量定义所在的复合语句时为它们分配存储&#…...

DBSCAN聚类算法及Python实现
DBSCAN聚类算法 DBSCAN(Density-Based Spatial Clustering of Applications with Noise)是一种基于密度的聚类算法,可以将数据点分成不同的簇,并且能够识别噪声点(不属于任何簇的点)。 DBSCAN聚类算法的基…...

风光及负荷多场景随机生成与缩减
目录 1 主要内容 计算模型 场景生成与聚类方法应用 2 部分程序 3 程序结果 4 程序链接 1 主要内容 该程序方法复现了《融合多场景分析的交直流混合微电网多时间尺度随机优化调度策略》3.1节基于多场景技术的随机性建模部分,该部分是随机优化调度的重要组成部分…...

lamda表达式
lamda表达式一. lamda表达式的特性二.常用匿名函数式接口2.1 Supplier接口2.2 Consumer接口2.3 Predicate接口2.4 Function接口2.5 BiFunction接口三.stream流传递先后顺序四.表达式4.1 ForEach4.2 Collect4.3 Filter4.4 Map4.5 MapToInt4.6 Distinct4.7 Sorted4.8 groupingBy4…...

MobTech 秒验|极速验证,拉新无忧
一、运营拓展新用户的难题 运营拓展新用户是每个应用都需要面对的问题,但是在实际操作中,往往会遇到一些困难。其中一个主要的难题就是注册和登录的繁琐性。用户在使用一个新的应用时,通常需要填写手机号、获取验证码、输入验证码等步骤&…...

大模型混战,阿里百度华为谁将成就AI时代的“新地基”?
从算力基础到用户生态,群雄逐鹿大模型 自2022年stable diffusion模型的进步推动AIGC的快速发展后,年底,ChatGPT以“破圈者”的姿态,快速“吸粉”亿万,在全球范围内掀起了一股AI浪潮,也促使了众多海外巨头竞…...

干翻Hadoop系列之:Hadoop前瞻之分布式知识
前言 一:海量数据价值 二:海量数据两个棘手问题 1:海量数据如何存储? 掌握分布式存储数据的思想。 A:方案1:单机存储磁盘不够加磁盘 限制问题: 1:一台计算机不能无限制拓充 2&a…...

MAE论文阅读《Masked Autoencoders Are Scalable Vision Learners》
文章目录动机方法写作方面参考Paper: https://arxiv.org/pdf/2111.06377.pdf 动机 首先简要介绍下BERT,NLP领域的BERT是基于Transformer架构,并采取无监督预训练的方式去训练模型。它提出的预训练方法在本质上是一种masked autoencoding,也就…...
代码随想录算法训练营第三十四天-贪心算法3| 1005.K次取反后最大化的数组和 134. 加油站 135. 分发糖果
1005. Maximize Sum Of Array After K Negations 参考视频:贪心算法,这不就是常识?还能叫贪心?LeetCode:1005.K次取反后最大化的数组和_哔哩哔哩_bilibili 贪心🔍 的思路,局部最优ÿ…...
比较系统的学习 pandas (2)
pandas 数据读取与输出方法和常用参数 1、读取 CSV文件 pd.read_csv("pathname",step,encoding"gbk",header"infer",name[],skip_blank_linesTrue,commentNone) path : 文件路径 step : 指定分隔符,默认为 逗号 enco…...
怎么查看电脑主板最大支持多少内存?
很多电脑,内存不够用,但应速度慢;还有一些就是买了很大的内存条,但是还是反应慢;这是为什么呢?我今天明白了,原来每个电脑都有自己的适配内存,就是每个电脑能支持多大的内存…...

数据结构——线段树
线段树的结构 线段树是一棵二叉树,其结点是一条“线段”——[a,b],它的左儿子和右儿子分别是这条线段的左半段和右半段,即[a, (ab)/2 ]和[(ab)/2 ,b]。线段树的叶子结点是长度为1的单位线段[a,a1]。下图就是一棵根为[1,10]的线段树࿱…...
【C++进阶】实现C++线程池
文章目录1. thread_pool.h2. main.cpp1. thread_pool.h #pragma once #include <iostream> #include <vector> #include <queue> #include <thread> #include <mutex> #include <condition_variable> #include <future> #include &…...
Redis常用五种数据类型
一、Redis String字符串 1.简介 String类型在redis中最常见的一种类型 string类型是二制安全的,可以存放字符串、数值、json、图像数据 value存储最大数据量是512M 2. 常用命令 set < key>< value>:添加键值对 nx:当数据库中…...
Python爬虫实战:研究MechanicalSoup库相关技术
一、MechanicalSoup 库概述 1.1 库简介 MechanicalSoup 是一个 Python 库,专为自动化交互网站而设计。它结合了 requests 的 HTTP 请求能力和 BeautifulSoup 的 HTML 解析能力,提供了直观的 API,让我们可以像人类用户一样浏览网页、填写表单和提交请求。 1.2 主要功能特点…...

K8S认证|CKS题库+答案| 11. AppArmor
目录 11. AppArmor 免费获取并激活 CKA_v1.31_模拟系统 题目 开始操作: 1)、切换集群 2)、切换节点 3)、切换到 apparmor 的目录 4)、执行 apparmor 策略模块 5)、修改 pod 文件 6)、…...

大型活动交通拥堵治理的视觉算法应用
大型活动下智慧交通的视觉分析应用 一、背景与挑战 大型活动(如演唱会、马拉松赛事、高考中考等)期间,城市交通面临瞬时人流车流激增、传统摄像头模糊、交通拥堵识别滞后等问题。以演唱会为例,暖城商圈曾因观众集中离场导致周边…...

DBAPI如何优雅的获取单条数据
API如何优雅的获取单条数据 案例一 对于查询类API,查询的是单条数据,比如根据主键ID查询用户信息,sql如下: select id, name, age from user where id #{id}API默认返回的数据格式是多条的,如下: {&qu…...
相机Camera日志分析之三十一:高通Camx HAL十种流程基础分析关键字汇总(后续持续更新中)
【关注我,后续持续新增专题博文,谢谢!!!】 上一篇我们讲了:有对最普通的场景进行各个日志注释讲解,但相机场景太多,日志差异也巨大。后面将展示各种场景下的日志。 通过notepad++打开场景下的日志,通过下列分类关键字搜索,即可清晰的分析不同场景的相机运行流程差异…...
3403. 从盒子中找出字典序最大的字符串 I
3403. 从盒子中找出字典序最大的字符串 I 题目链接:3403. 从盒子中找出字典序最大的字符串 I 代码如下: class Solution { public:string answerString(string word, int numFriends) {if (numFriends 1) {return word;}string res;for (int i 0;i &…...
Caliper 配置文件解析:config.yaml
Caliper 是一个区块链性能基准测试工具,用于评估不同区块链平台的性能。下面我将详细解释你提供的 fisco-bcos.json 文件结构,并说明它与 config.yaml 文件的关系。 fisco-bcos.json 文件解析 这个文件是针对 FISCO-BCOS 区块链网络的 Caliper 配置文件,主要包含以下几个部…...
MySQL用户和授权
开放MySQL白名单 可以通过iptables-save命令确认对应客户端ip是否可以访问MySQL服务: test: # iptables-save | grep 3306 -A mp_srv_whitelist -s 172.16.14.102/32 -p tcp -m tcp --dport 3306 -j ACCEPT -A mp_srv_whitelist -s 172.16.4.16/32 -p tcp -m tcp -…...

零基础在实践中学习网络安全-皮卡丘靶场(第九期-Unsafe Fileupload模块)(yakit方式)
本期内容并不是很难,相信大家会学的很愉快,当然对于有后端基础的朋友来说,本期内容更加容易了解,当然没有基础的也别担心,本期内容会详细解释有关内容 本期用到的软件:yakit(因为经过之前好多期…...
【无标题】路径问题的革命性重构:基于二维拓扑收缩色动力学模型的零点隧穿理论
路径问题的革命性重构:基于二维拓扑收缩色动力学模型的零点隧穿理论 一、传统路径模型的根本缺陷 在经典正方形路径问题中(图1): mermaid graph LR A((A)) --- B((B)) B --- C((C)) C --- D((D)) D --- A A -.- C[无直接路径] B -…...