memory

package
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 Go to latest Published: Aug 23, 2023 License: Apache-2.0 Imports: 19 Imported by: 0

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Constants

View Source 
const (
	DefPanicPriority = iota
	DefLogPriority
	DefSpillPriority
	// DefCursorFetchSpillPriority is higher than normal disk spill, because it can release much more memory in the future.
	// And the performance impaction of it is less than other disk-spill action, because it's write-only in execution stage.
	DefCursorFetchSpillPriority
	DefRateLimitPriority
)

Default OOM Action priority.

View Source 
const (
	// PanicMemoryExceedWarnMsg represents the panic message when out of memory quota.
	PanicMemoryExceedWarnMsg string = "Your query has been cancelled due to exceeding the allowed memory limit"
	// WarnMsgSuffixForSingleQuery represents the suffix of the warning message when out of memory quota for a single query.
	WarnMsgSuffixForSingleQuery string = " for a single SQL query. Please try narrowing your query scope or increase the tidb_mem_quota_query limit and try again."
	// WarnMsgSuffixForInstance represents the suffix of the warning message when out of memory quota for the tidb-server instance.
	WarnMsgSuffixForInstance string = "" /* 174-byte string literal not displayed */
)
View Source 
const (
	// LabelForSQLText represents the label of the SQL Text
	LabelForSQLText int = -1
	// LabelForIndexWorker represents the label of the index worker
	LabelForIndexWorker int = -2
	// LabelForInnerList represents the label of the inner list
	LabelForInnerList int = -3
	// LabelForInnerTable represents the label of the inner table
	LabelForInnerTable int = -4
	// LabelForOuterTable represents the label of the outer table
	LabelForOuterTable int = -5
	// LabelForCoprocessor represents the label of the coprocessor
	LabelForCoprocessor int = -6
	// LabelForChunkList represents the label of the chunk list
	LabelForChunkList int = -7
	// LabelForGlobalSimpleLRUCache represents the label of the Global SimpleLRUCache
	LabelForGlobalSimpleLRUCache int = -8
	// LabelForChunkListInDisk represents the label of the chunk list in disk
	LabelForChunkListInDisk int = -9
	// LabelForRowContainer represents the label of the row container
	LabelForRowContainer int = -10
	// LabelForGlobalStorage represents the label of the Global Storage
	LabelForGlobalStorage int = -11
	// LabelForGlobalMemory represents the label of the Global Memory
	LabelForGlobalMemory int = -12
	// LabelForBuildSideResult represents the label of the BuildSideResult
	LabelForBuildSideResult int = -13
	// LabelForRowChunks represents the label of the row chunks
	LabelForRowChunks int = -14
	// LabelForStatsCache represents the label of the stats cache
	LabelForStatsCache int = -15
	// LabelForOuterList represents the label of the outer list
	LabelForOuterList int = -16
	// LabelForApplyCache represents the label of the apply cache
	LabelForApplyCache int = -17
	// LabelForSimpleTask represents the label of the simple task
	LabelForSimpleTask int = -18
	// LabelForCTEStorage represents the label of CTE storage
	LabelForCTEStorage int = -19
	// LabelForIndexJoinInnerWorker represents the label of IndexJoin InnerWorker
	LabelForIndexJoinInnerWorker int = -20
	// LabelForIndexJoinOuterWorker represents the label of IndexJoin OuterWorker
	LabelForIndexJoinOuterWorker int = -21
	// LabelForBindCache represents the label of the bind cache
	LabelForBindCache int = -22
	// LabelForNonTransactionalDML represents the label of the non-transactional DML
	LabelForNonTransactionalDML = -23
	// LabelForAnalyzeMemory represents the label of the memory of each analyze job
	LabelForAnalyzeMemory int = -24
	// LabelForGlobalAnalyzeMemory represents the label of the global memory of all analyze jobs
	LabelForGlobalAnalyzeMemory int = -25
	// LabelForPreparedPlanCache represents the label of the prepared plan cache memory usage
	LabelForPreparedPlanCache int = -26
	// LabelForSession represents the label of a session.
	LabelForSession int = -27
	// LabelForMemDB represents the label of the MemDB
	LabelForMemDB int = -28
	// LabelForCursorFetch represents the label of the execution of cursor fetch
	LabelForCursorFetch int = -29
)
View Source 
const ReadMemInterval = 300 * time.Millisecond

ReadMemInterval controls the interval to read memory stats.

View Source 
const TrackMemWhenExceeds = 104857600 // 100MB

TrackMemWhenExceeds is the threshold when memory usage needs to be tracked.

Variables

View Source 
var (
	ServerMemoryLimitOriginText  = atomicutil.NewString("0")
	ServerMemoryLimit            = atomicutil.NewUint64(0)
	ServerMemoryLimitSessMinSize = atomicutil.NewUint64(128 << 20)

	QueryForceDisk       = atomicutil.NewInt64(0)
	TriggerMemoryLimitGC = atomicutil.NewBool(false)
	MemoryLimitGCLast    = atomicutil.NewTime(time.Time{})
	MemoryLimitGCTotal   = atomicutil.NewInt64(0)
)

Process global variables for memory limit.

View Source 
var EnableGCAwareMemoryTrack = atomicutil.NewBool(false)

EnableGCAwareMemoryTrack is used to turn on/off the GC-aware memory track

View Source 
var MemTotal func() (uint64, error)

MemTotal returns the total amount of RAM on this system

View Source 
var MemUsageTop1Tracker atomic.Pointer[Tracker]

MemUsageTop1Tracker record the use memory top1 session's tracker for kill.

View Source 
var MemUsed func() (uint64, error)

MemUsed returns the total used amount of RAM on this system

View Source 
var MetricsTypes = map[int][]string{
	LabelForGlobalAnalyzeMemory: {"analyze", "inuse", "released"},
}

MetricsTypes is used to get label for metrics string[0] is LblModule, string[1] is heap-in-use type, string[2] is released type

Functions

func BytesToString 

func BytesToString(numBytes int64) string

BytesToString converts the memory consumption to a readable string.

func ForceReadMemStats 

func ForceReadMemStats() *runtime.MemStats

ForceReadMemStats is to force read memory stats.

func FormatBytes 

func FormatBytes(numBytes int64) string

FormatBytes uses to format bytes, this function will prune precision before format bytes.

func GetMemTotalIgnoreErr 

func GetMemTotalIgnoreErr() uint64

GetMemTotalIgnoreErr returns the total amount of RAM on this system/container. If error occurs, return 0.

func InitTracker 

func InitTracker(t *Tracker, label int, bytesLimit int64, action ActionOnExceed)

InitTracker initializes a memory tracker.

  1. "label" is the label used in the usage string.
  2. "bytesLimit <= 0" means no limit.

For the common tracker, isGlobal is default as false

func InstanceMemUsed 

func InstanceMemUsed() (uint64, error)

InstanceMemUsed returns the memory usage of this TiDB server

func MemTotalCGroup 

func MemTotalCGroup() (uint64, error)

MemTotalCGroup returns the total amount of RAM on this system in container environment.

func MemTotalNormal 

func MemTotalNormal() (uint64, error)

MemTotalNormal returns the total amount of RAM on this system in non-container environment.

func MemUsedCGroup 

func MemUsedCGroup() (uint64, error)

MemUsedCGroup returns the total used amount of RAM on this system in container environment.

func MemUsedNormal 

func MemUsedNormal() (uint64, error)

MemUsedNormal returns the total used amount of RAM on this system in non-container environment.

func NewActionWithPriority 

func NewActionWithPriority(action ActionOnExceed, priority int64) *actionWithPriority

NewActionWithPriority wraps the action with a new priority

func ReadMemStats 

func ReadMemStats() (memStats *runtime.MemStats)

ReadMemStats read the mem stats from runtime.ReadMemStats

Types

type ActionCareInvoker 

type ActionCareInvoker interface {
	SetInvoker(invoker ActionInvoker)
}

ActionCareInvoker is the interface for the Actions which need to be aware of the invoker.

type ActionInvoker 

type ActionInvoker byte

ActionInvoker indicates the invoker of the Action. 

const (
	// SingleQuery indicates the Action is invoked by a tidb_mem_quota_query.
	SingleQuery ActionInvoker = iota
	// Instance indicates the Action is invoked by a tidb_server_memory_limit.
	Instance
)

type ActionOnExceed 

type ActionOnExceed interface {
	// Action will be called when memory usage exceeds memory quota by the
	// corresponding Tracker.
	Action(t *Tracker)
	// SetFallback sets a fallback action which will be triggered if itself has
	// already been triggered.
	SetFallback(a ActionOnExceed)
	// GetFallback get the fallback action of the Action.
	GetFallback() ActionOnExceed
	// GetPriority get the priority of the Action.
	GetPriority() int64
	// SetFinished sets the finished state of the Action.
	SetFinished()
	// IsFinished returns the finished state of the Action.
	IsFinished() bool
}

ActionOnExceed is the action taken when memory usage exceeds memory quota. NOTE: All the implementors should be thread-safe.

type BaseOOMAction 

type BaseOOMAction struct {
	// contains filtered or unexported fields
}

BaseOOMAction manages the fallback action for all Action.

func (*BaseOOMAction) GetFallback 

func (b *BaseOOMAction) GetFallback() ActionOnExceed

GetFallback get the fallback action and remove finished fallback.

func (*BaseOOMAction) IsFinished 

func (b *BaseOOMAction) IsFinished() bool

IsFinished returns the finished state of the Action.

func (*BaseOOMAction) SetFallback 

func (b *BaseOOMAction) SetFallback(a ActionOnExceed)

SetFallback sets a fallback action which will be triggered if itself has already been triggered.

func (*BaseOOMAction) SetFinished 

func (b *BaseOOMAction) SetFinished()

SetFinished sets the finished state of the Action.

type LogOnExceed 

type LogOnExceed struct {
	BaseOOMAction
	ConnID uint64
	// contains filtered or unexported fields
}

LogOnExceed logs a warning only once when memory usage exceeds memory quota.

func (*LogOnExceed) Action 

func (a *LogOnExceed) Action(t *Tracker)

Action logs a warning only once when memory usage exceeds memory quota.

func (*LogOnExceed) GetPriority 

func (*LogOnExceed) GetPriority() int64

GetPriority get the priority of the Action

func (*LogOnExceed) SetLogHook 

func (a *LogOnExceed) SetLogHook(hook func(uint64))

SetLogHook sets a hook for LogOnExceed.

type PanicOnExceed 

type PanicOnExceed struct {
	BaseOOMAction
	ConnID uint64
	// contains filtered or unexported fields
}

PanicOnExceed panics when memory usage exceeds memory quota.

func (*PanicOnExceed) Action 

func (a *PanicOnExceed) Action(t *Tracker)

Action panics when memory usage exceeds memory quota.

func (*PanicOnExceed) GetPriority 

func (*PanicOnExceed) GetPriority() int64

GetPriority get the priority of the Action

func (*PanicOnExceed) SetInvoker 

func (a *PanicOnExceed) SetInvoker(invoker ActionInvoker)

SetInvoker sets the invoker of the Action.

func (*PanicOnExceed) SetLogHook 

func (a *PanicOnExceed) SetLogHook(hook func(uint64))

SetLogHook sets a hook for PanicOnExceed.

type Tracker 

type Tracker struct {
	SessionID           atomicutil.Uint64 // SessionID indicates the sessionID the tracker is bound.
	NeedKill            atomic.Bool       // NeedKill indicates whether this session need kill because OOM
	NeedKillReceived    sync.Once
	IsRootTrackerOfSess bool // IsRootTrackerOfSess indicates whether this tracker is bound for session
	// contains filtered or unexported fields
}

Tracker is used to track the memory usage during query execution. It contains an optional limit and can be arranged into a tree structure such that the consumption tracked by a Tracker is also tracked by its ancestors. The main idea comes from Apache Impala:

https://github.com/cloudera/Impala/blob/cdh5-trunk/be/src/runtime/mem-tracker.h

By default, memory consumption is tracked via calls to "Consume()", either to the tracker itself or to one of its descendents. A typical sequence of calls for a single Tracker is: 1. tracker.SetLabel() / tracker.SetActionOnExceed() / tracker.AttachTo() 2. tracker.Consume() / tracker.ReplaceChild() / tracker.BytesConsumed()

NOTE: We only protect concurrent access to "bytesConsumed" and "children", that is to say: 1. Only "BytesConsumed()", "Consume()" and "AttachTo()" are thread-safe. 2. Other operations of a Tracker tree is not thread-safe.

We have two limits for the memory quota: soft limit and hard limit. If the soft limit is exceeded, we will trigger the action that alleviates the speed of memory growth. The soft limit is hard-coded as `0.8*hard limit`. The actions that could be triggered are: AggSpillDiskAction.

If the hard limit is exceeded, we will trigger the action that immediately reduces memory usage. The hard limit is set by the system variable `tidb_mem_query_quota`. The actions that could be triggered are: SpillDiskAction, SortAndSpillDiskAction, rateLimitAction, PanicOnExceed, globalPanicOnExceed, LogOnExceed.

func NewGlobalTracker 

func NewGlobalTracker(label int, bytesLimit int64) *Tracker

NewGlobalTracker creates a global tracker, its isGlobal is default as true

func NewTracker 

func NewTracker(label int, bytesLimit int64) *Tracker

NewTracker creates a memory tracker.

  1. "label" is the label used in the usage string.
  2. "bytesLimit <= 0" means no limit.

For the common tracker, isGlobal is default as false

func (*Tracker) AttachTo 

func (t *Tracker) AttachTo(parent *Tracker)

AttachTo attaches this memory tracker as a child to another Tracker. If it already has a parent, this function will remove it from the old parent. Its consumed memory usage is used to update all its ancestors.

func (*Tracker) AttachToGlobalTracker 

func (t *Tracker) AttachToGlobalTracker(globalTracker *Tracker)

AttachToGlobalTracker attach the tracker to the global tracker AttachToGlobalTracker should be called at the initialization for the session executor's tracker

func (*Tracker) BufferedConsume 

func (t *Tracker) BufferedConsume(bufferedMemSize *int64, bytes int64)

BufferedConsume is used to buffer memory usage and do late consume not thread-safe, should be called in one goroutine

func (*Tracker) BufferedRelease 

func (t *Tracker) BufferedRelease(bufferedMemSize *int64, bytes int64)

BufferedRelease is used to buffer memory release and do late release not thread-safe, should be called in one goroutine

func (*Tracker) BytesConsumed 

func (t *Tracker) BytesConsumed() int64

BytesConsumed returns the consumed memory usage value in bytes.

func (*Tracker) BytesReleased 

func (t *Tracker) BytesReleased() int64

BytesReleased returns the released memory value in bytes.

func (*Tracker) CheckBytesLimit 

func (t *Tracker) CheckBytesLimit(val int64) bool

CheckBytesLimit check whether the bytes limit of the tracker is equal to a value. Only used in test.

func (*Tracker) CheckExceed 

func (t *Tracker) CheckExceed() bool

CheckExceed checks whether the consumed bytes is exceed for this tracker.

func (*Tracker) Consume 

func (t *Tracker) Consume(bs int64)

Consume is used to consume a memory usage. "bytes" can be a negative value, which means this is a memory release operation. When memory usage of a tracker exceeds its bytesSoftLimit/bytesHardLimit, the tracker calls its action, so does each of its ancestors.

func (*Tracker) CountAllChildrenMemUse 

func (t *Tracker) CountAllChildrenMemUse() map[string]int64

CountAllChildrenMemUse return memory used tree for the tracker

func (*Tracker) Detach 

func (t *Tracker) Detach()

Detach de-attach the tracker child from its parent, then set its parent property as nil

func (*Tracker) DetachFromGlobalTracker 

func (t *Tracker) DetachFromGlobalTracker()

DetachFromGlobalTracker detach itself from its parent Note that only the parent of this tracker is Global Tracker could call this function Otherwise it should use Detach

func (*Tracker) FallbackOldAndSetNewAction 

func (t *Tracker) FallbackOldAndSetNewAction(a ActionOnExceed)

FallbackOldAndSetNewAction sets the action when memory usage exceeds bytesHardLimit and set the original action as its fallback.

func (*Tracker) FallbackOldAndSetNewActionForSoftLimit 

func (t *Tracker) FallbackOldAndSetNewActionForSoftLimit(a ActionOnExceed)

FallbackOldAndSetNewActionForSoftLimit sets the action when memory usage exceeds bytesSoftLimit and set the original action as its fallback.

func (*Tracker) FormatBytes 

func (*Tracker) FormatBytes(numBytes int64) string

FormatBytes uses to format bytes, this function will prune precision before format bytes.

func (*Tracker) GetBytesLimit 

func (t *Tracker) GetBytesLimit() int64

GetBytesLimit gets the bytes limit for this tracker. "bytesHardLimit <= 0" means no limit.

func (*Tracker) GetChildrenForTest 

func (t *Tracker) GetChildrenForTest() []*Tracker

GetChildrenForTest returns children trackers

func (*Tracker) GetFallbackForTest 

func (t *Tracker) GetFallbackForTest(ignoreFinishedAction bool) ActionOnExceed

GetFallbackForTest get the oom action used by test.

func (*Tracker) Label 

func (t *Tracker) Label() int

Label gets the label of a Tracker.

func (*Tracker) LessThan 

func (t *Tracker) LessThan(t2 *Tracker) bool

LessThan indicates whether t byteConsumed is less than t2 byteConsumed.

func (*Tracker) MaxConsumed 

func (t *Tracker) MaxConsumed() int64

MaxConsumed returns max number of bytes consumed during execution. Note: Don't make this method return -1 for special meanings in the future. Because binary plan has used -1 to distinguish between "0 bytes" and "N/A". ref: binaryOpFromFlatOp()

func (*Tracker) Release 

func (t *Tracker) Release(bytes int64)

Release is used to release memory tracked, track the released memory until GC triggered if needed If you want your track to be GC-aware, please use Release(bytes) instead of Consume(-bytes), and pass the memory size of the real object. Only Analyze is integrated with Release so far.

func (*Tracker) ReplaceBytesUsed 

func (t *Tracker) ReplaceBytesUsed(bytes int64)

ReplaceBytesUsed replace bytesConsume for the tracker

func (*Tracker) ReplaceChild 

func (t *Tracker) ReplaceChild(oldChild, newChild *Tracker)

ReplaceChild removes the old child specified in "oldChild" and add a new child specified in "newChild". old child's memory consumption will be removed and new child's memory consumption will be added.

func (*Tracker) Reset 

func (t *Tracker) Reset()

Reset detach the tracker from the old parent and clear the old children. The label and byteLimit would not be reset.

func (*Tracker) ResetMaxConsumed 

func (t *Tracker) ResetMaxConsumed()

ResetMaxConsumed should be invoked before executing a new statement in a session.

func (*Tracker) SearchTrackerConsumedMoreThanNBytes 

func (t *Tracker) SearchTrackerConsumedMoreThanNBytes(limit int64) (res []*Tracker)

SearchTrackerConsumedMoreThanNBytes searches the specific tracker that consumes more than NBytes.

func (*Tracker) SearchTrackerWithoutLock 

func (t *Tracker) SearchTrackerWithoutLock(label int) *Tracker

SearchTrackerWithoutLock searches the specific tracker under this tracker without lock.

func (*Tracker) SetActionOnExceed 

func (t *Tracker) SetActionOnExceed(a ActionOnExceed)

SetActionOnExceed sets the action when memory usage exceeds bytesHardLimit.

func (*Tracker) SetBytesLimit 

func (t *Tracker) SetBytesLimit(bytesLimit int64)

SetBytesLimit sets the bytes limit for this tracker. "bytesHardLimit <= 0" means no limit.

func (*Tracker) SetLabel 

func (t *Tracker) SetLabel(label int)

SetLabel sets the label of a Tracker.

func (*Tracker) String 

func (t *Tracker) String() string

String returns the string representation of this Tracker tree.

func (*Tracker) UnbindActions 

func (t *Tracker) UnbindActions()

UnbindActions unbinds actionForHardLimit and actionForSoftLimit.

Source Files

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