citus/src/include/distributed/utils/citus_stat_tenants.h

121 lines
3.3 KiB
C

/*-------------------------------------------------------------------------
*
* citus_stat_tenants.h
* Routines related to the multi tenant monitor.
*
* Copyright (c) Citus Data, Inc.
*
*-------------------------------------------------------------------------
*/
#ifndef CITUS_ATTRIBUTE_H
#define CITUS_ATTRIBUTE_H
#include "executor/execdesc.h"
#include "executor/executor.h"
#include "storage/lwlock.h"
#include "utils/datetime.h"
#define MAX_TENANT_ATTRIBUTE_LENGTH 100
/*
* TenantStats is the struct that keeps statistics about one tenant.
*/
typedef struct TenantStats
{
/*
* The attribute value, e.g distribution column, and colocation group id
* of the tenant.
*/
char tenantAttribute[MAX_TENANT_ATTRIBUTE_LENGTH];
int colocationGroupId;
/*
* Number of SELECT queries this tenant ran in this and last periods.
*/
int readsInLastPeriod;
int readsInThisPeriod;
/*
* Number of INSERT, UPDATE, and DELETE queries this tenant ran in this and last periods.
*/
int writesInLastPeriod;
int writesInThisPeriod;
/*
* CPU time usage of this tenant in this and last periods.
*/
double cpuUsageInLastPeriod;
double cpuUsageInThisPeriod;
/*
* The latest time this tenant ran a query. This value is used to update the score later.
*/
TimestampTz lastQueryTime;
/*
* The tenant monitoring score of this tenant. This value is increased by ONE_QUERY_SCORE at every query
* and halved after every period. This custom scoring mechanism is used to rank the tenants based on
* the recency and frequency of their activity. The score is used to rank the tenants and decide which
* tenants should be removed from the monitor.
*/
long long score;
/*
* The latest time the score of this tenant is halved. This value is used to correctly calculate the reduction later.
*/
TimestampTz lastScoreReduction;
/*
* Locks needed to update this tenant's statistics.
*/
NamedLWLockTranche namedLockTranche;
LWLock lock;
} TenantStats;
/*
* MultiTenantMonitor is the struct for keeping the statistics
* of the tenants
*/
typedef struct MultiTenantMonitor
{
/*
* Lock mechanism for the monitor.
* Each tenant update acquires the lock in shared mode and
* the tenant number reduction and monitor view acquires in exclusive mode.
*/
NamedLWLockTranche namedLockTranche;
LWLock lock;
/*
* tenantCount is the number of items in the tenants array.
* The total length of tenants array is set up at CreateSharedMemoryForMultiTenantMonitor
* and is 3 * citus.stat_tenants_limit
*/
int tenantCount;
TenantStats tenants[FLEXIBLE_ARRAY_MEMBER];
} MultiTenantMonitor;
typedef enum
{
STAT_TENANTS_TRACK_NONE = 0,
STAT_TENANTS_TRACK_ALL = 1
} StatTenantsTrackType;
extern void CitusAttributeToEnd(QueryDesc *queryDesc);
extern void AttributeQueryIfAnnotated(const char *queryString, CmdType commandType);
extern char * AnnotateQuery(char *queryString, Const *partitionKeyValue,
int colocationId);
extern void InitializeMultiTenantMonitorSMHandleManagement(void);
extern void AttributeTask(char *tenantId, int colocationGroupId, CmdType commandType);
extern ExecutorEnd_hook_type prev_ExecutorEnd;
extern int StatTenantsLogLevel;
extern int StatTenantsPeriod;
extern int StatTenantsLimit;
extern int StatTenantsTrack;
#endif /*CITUS_ATTRIBUTE_H */