tencent cloud

Overview

Cluster events include event lists and event policies.

• Event list: It records key change events and abnormal events occurring in the cluster.
• Event policy: Event monitoring trigger policies can be customized based on the actual business conditions. Events with monitoring enabled can be set as cluster inspection items.

Viewing Event List

1. Log in to the EMR console and click the ID/Name of the target cluster in the cluster list to enter the cluster details page.
2. On the cluster details page, select Cluster Monitoring > Cluster Events > Event List to view all operation events in the current cluster.
   
   The severity divides into the following:

• Fatal: Exception events of a node or service that require manual intervention and will cause service interruption if left unattended. Such events may last for a period of time.
• Severe: Alert events that currently have not caused service or node interruption but will cause fatal events if left unattended.
• Moderate: Regular events occurring in the cluster that generally do not require special processing.

Setting Event Policy

1. Log in to the EMR console and click the ID/Name of the target cluster in the cluster list to enter the cluster details page.
2. On the cluster details page, select Cluster Monitoring > Cluster Events > Event Policy and you can customize the event monitoring trigger policies.
3. The event configuration list contains the event name, event trigger policy, severity (fatal, severe, and moderate), and option to enable/disable monitoring, which can be modified and saved.
   
4. Event trigger policies cover two types of events: fixed system policy events (which cannot be modified) and custom events (which can be configured based on the business standards).
   
5. You can select whether to enable event monitoring in an event policy. Only events with monitoring enabled can be selected as cluster inspection items. Monitoring is enabled by default for some events and is enabled by default and cannot be disabled for some other events. The following are the specific rules:

   Type	Event	Description	Recommended Measure	Default Value	Severity	Disableable	Enabled by Default
   Node	The CPU utilization exceeds the threshold continuously	The server CPU utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=85, t=1800	Severe	Yes	Yes
   	The average CPU utilization exceeds the threshold	The average server CPU utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=85, t=1800	Moderate	Yes	No
   	The average CPU iowait utilization exceeds the threshold	The average CPU iowait utilization of the server in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Troubleshoot	m=60, t=1800	Severe	Yes	Yes
   	The 1-second CPU load exceeds the threshold continuously	The 1-minute CPU load has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=8, t=1800	Moderate	Yes	No
   	The 5-second CPU load exceeds the threshold continuously	The 5-minute CPU load has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=8, t=1800	Severe	Yes	No
   	The memory utilization exceeds the threshold continuously	The memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=85, t=1800	Severe	Yes	Yes
   	The swap space exceeds the threshold continuously	The server swap memory has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=0.1, t=300	Moderate	Yes	No
   	The total number of system processes exceeds the threshold continuously	The total number of system processes has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=10000, t=1800	Severe	Yes	Yes
   	The average total number of fork subprocesses exceeds the threshold	The average total number of fork subprocesses in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Troubleshoot	m=5000, t=1800	Moderate	Yes	No
   	The process does not exist due to OOM	An OOM error occurred in the process	Adjust the process heap memory size	-	Severe	No	Yes
   	A disk I/O error occurred (this event is not supported currently)	A disk I/O error occurred	Replace the disk	-	Fatal	Yes	Yes
   	The disk space utilization exceeds the threshold continuously	The disk space utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=85, t=1800	Severe	Yes	Yes
   	The disk I/O device utilization exceeds the threshold continuously	The disk I/O device utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=85, t=1800	Severe	Yes	Yes
   	The node file handle utilization exceeds the threshold continuously	The node file handle utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=85, t=1800	Moderate	Yes	No
   	The number of TCP connections to the node exceeds the threshold continuously	The number of TCP connections to the node has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Check whether there are connection leaks	m=10000, t=1800	Moderate	Yes	No
   	The configured node memory utilization exceeds the threshold	The memory utilization configured for all roles on the node exceeds the node's physical memory threshold	Adjust the allocated node process heap memory	90%	Severe	Yes	No
   	The node process is unavailable	The node service process is unavailable	View the service logs to find out why the service failed to be pulled	-	Moderate	Yes	Yes
   	The node heartbeat is missing	The node heartbeat failed to be reported regularly	Troubleshoot	-	Fatal	No	Yes
   	Incorrect hostname	The node's hostname is incorrect	Troubleshoot	-	Fatal	No	Yes
   	Failed to ping the metadatabase	The TencentDB instance heartbeat failed to be reported regularly	-	-	-	-	-
   HDFS	The total number of HDFS files exceeds the threshold continuously	The total number of files in the cluster has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Increase the NameNode memory	m=50,000,000, t=1800	Severe	Yes	No
   	The average total number of HDFS files exceeds the threshold	The average total number of files in the cluster in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Increase the NameNode memory	m=50,000,000, t=1800	Severe	Yes	No
   	The total number of HDFS blocks exceeds the threshold continuously	The total number of blocks in the cluster has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Increase the NameNode memory or the block size	m=50,000,000, t=1800	Severe	Yes	No
   	The average total number of HDFS blocks exceeds the threshold	The average total number of HDFS blocks in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Increase the NameNode memory or the block size	m=50,000,000, t=1800	Severe	Yes	No
   	The number of HDFS data nodes marked as dead exceeds the threshold continuously	The number of data nodes marked as dead has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=1, t=1800	Moderate	Yes	No
   	The HDFS storage space utilization exceeds the threshold continuously	The HDFS storage space utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Clear files in HDFS or expand the cluster capacity	m=85, t=1800	Severe	Yes	Yes
   	The average HDFS storage space utilization exceeds the threshold	The average HDFS storage space utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Clear files in HDFS or expand the cluster capacity	m=85, t=1800	Severe	Yes	No
   	Active/Standby NameNodes were switched	Active/Standby NameNodes were switched	Locate the cause of NameNode switch	-	Severe	Yes	Yes
   	The NameNode RPC request processing latency exceeds the threshold continuously	The RPC request processing latency has been greater than or equal to m milliseconds for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=300, t=300	Severe	Yes	No
   	The number of current NameNode connections exceeds the threshold continuously	The number of current NameNode connections has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=2000, t=1800	Moderate	Yes	No
   	A full GC event occurred on a NameNode	A full GC event occurred on a NameNode	Fine-tune the parameter settings	-	Severe	Yes	Yes
   	The NameNode JVM memory utilization exceeds the threshold continuously	The NameNode JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the NameNode heap memory size	m=85, t=1800	Severe	Yes	Yes
   	The DataNode RPC request processing latency exceeds the threshold continuously	The RPC request processing latency has been greater than or equal to m milliseconds for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=300, t=300	Moderate	Yes	No
   	The number of current DataNode connections exceeds the threshold continuously	The number of current DataNode connections has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=2000, t=1800	Moderate	Yes	No
   	A full GC event occurred on a DataNode	A full GC event occurred on a NameNode	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The DataNode JVM memory utilization exceeds the threshold continuously	The NameNode JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the DataNode heap memory size	m=85, t=1800	Moderate	Yes	Yes
   YARN	The number of currently missing NodeManagers in the cluster exceeds the threshold continuously	The number of currently missing NodeManagers in the cluster has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Check the NodeManager process status and check whether the network connection is smooth	m=1, t=1800	Moderate	Yes	No
   	The number of pending containers exceeds the threshold continuously	The number of pending containers has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Reasonably specify resources that can be used by YARN jobs	m=90, t=1800	Moderate	Yes	No
   	The cluster memory utilization exceeds the threshold continuously	The memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the cluster capacity	m=85, t=1800	Severe	Yes	Yes
   	The average cluster memory utilization exceeds the threshold	The average memory utilization in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Expand the cluster capacity	m=85, t=1800	Severe	Yes	No
   	The cluster CPU utilization exceeds the threshold continuously	The CPU utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the cluster capacity	m=85, t=1800	Severe	Yes	Yes
   	The average cluster CPU utilization exceeds the threshold	The average CPU utilization in the last t (300 ≤ t ≤ 2,592,000) seconds has been greater than or equal to m	Expand the cluster capacity	m=85, t=1800	Severe	Yes	No
   	The number of available CPU cores in each queue is below the threshold continuously.	The number of available CPU cores in each queue has been less than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Assign more resources to the queue	m=1, t=1800	Moderate	Yes	No
   	The available memory in each queue is below the threshold continuously	The available memory in each queue has been less than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Assign more resources to the queue	m=1024, t=1800	Moderate	Yes	No
   	Active/Standby ResourceManagers were switched	Active/Standby ResourceManagers were switched	Check the ResourceManager process status and view the standby ResourceManager logs to locate the cause of active/standby switch	-	Severe	Yes	Yes
   	A full GC event occurred in a ResourceManager	A full GC event occurred in a ResourceManager	Fine-tune the parameter settings	-	Severe	Yes	Yes
   	The ResourceManager JVM memory utilization exceeds the threshold continuously	The ResourceManager JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the ResourceManager heap memory size	m=85, t=1800	Severe	Yes	Yes
   	A full GC event occurred in a NodeManager	A full GC event occurred in a NodeManager	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The available memory in NodeManager is below the threshold continuously	The available memory in a single NodeManager has been less than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the NodeManager heap memory size	m=1, t=1800	Moderate	Yes	No
   	The NodeManager JVM memory utilization exceeds the threshold continuously	The NodeManager JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the NodeManager heap memory size	m=85, t=1800	Moderate	Yes	No
   HBase	The number of regions in RIT status in the cluster exceeds the threshold continuously	The number of regions in RIT status in the cluster has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	If the HBase version is below 2.0, run `hbase hbck -fixAssigment`	m=1, t=60	Severe	Yes	Yes
   	The number of dead RegionServers exceeds the threshold continuously	The number of dead RegionServers has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=1, t=300	Moderate	Yes	Yes
   	The average number of regions in each RegionServer in the cluster exceeds the threshold continuously	The average number of regions in each RegionServer in the cluster has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Expand the node capacity or upgrade the node	m=300, t=1800	Moderate	Yes	Yes
   	A full GC event occurred on HMaster	A full GC event occurred on HMaster	Fine-tune the parameter settings	m=5, t=300	Moderate	Yes	Yes
   	The HMaster JVM memory utilization exceeds the threshold continuously	The HMaster JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the HMaster heap memory size	m=85, t=1800	Severe	Yes	Yes
   	The number of current HMaster connections exceeds the threshold continuously	The number of current HMaster connections has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=1000, t=1800	Moderate	Yes	No
   	A full GC event occurred in RegionServer	A full GC event occurred in RegionServer	Fine-tune the parameter settings	m=5, t=300	Severe	Yes	No
   	The RegionServer JVM memory utilization exceeds the threshold continuously	The RegionServer JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the RegionServer heap memory size	m=85, t=1800	Moderate	Yes	No
   	The number of current RPC connections to RegionServer exceeds the threshold continuously	The number of current RPC connections to RegionServer has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=1000, t=1800	Moderate	Yes	No
   	The number of RegionServer StoreFiles exceeds the threshold continuously	The number of RegionServer StoreFiles has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Run the major compaction	m=50000, t=1800	Moderate	Yes	No
   	A full GC event occurred in HBase Thrift	A full GC event occurred in HBase Thrift	Fine-tune the parameter settings	m=5, t=300	Severe	Yes	No
   	The HBase Thrift JVM memory utilization exceeds the threshold continuously	The HBase Thrift JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the HBase Thrift heap memory size	m=85, t=1800	Moderate	Yes	No
   Hive	A full GC event occurred in HiveServer2	A full GC event occurred in HiveServer2	Fine-tune the parameter settings	m=5, t=300	Severe	Yes	Yes
   	The HiveServer2 JVM memory utilization exceeds the threshold continuously	The HiveServer2 JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Adjust the HiveServer2 heap memory size	m=85, t=1800	Severe	Yes	Yes
   	A full GC event occurred in HiveMetaStore	A full GC event occurred in HiveMetaStore	Fine-tune the parameter settings	m=5, t=300	Moderate	Yes	Yes
   	A full GC event occurred in HiveWebHcat	A full GC event occurred in HiveWebHcat	Fine-tune the parameter settings	m=5, t=300	Moderate	Yes	Yes
   ZooKeeper	The number of ZooKeeper connections exceeds the threshold continuously	The number of ZooKeeper connections has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=65535, t=1800	Moderate	Yes	No
   	The number of ZNodes exceeds the threshold continuously	The number of ZNodes has been greater than or equal to m for t (300 ≤ t ≤ 2,592,000) seconds continuously	Troubleshoot	m=2000, t=1800	Moderate	Yes	No
   Impala	The ImpalaCatalog JVM memory utilization exceeds the threshold continuously	The ImpalaCatalog JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the ImpalaCatalog heap memory size	m=0.85, t=1800	Moderate	Yes	No
   	The Impala daemon JVM memory utilization exceeds the threshold continuously	The Impala daemon JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the ImpalaDaemon heap memory size	m=0.85, t=1800	Moderate	Yes	No
   	The number of Impala Beeswax API client connections exceeds the threshold	The number of Impala Beeswax API client connections has been greater than or equal to m	Adjust the value of `fs_sevice_threads` in the `impalad.flgs` configuration in the console	m=64,t=120	Severe	Yes	Yes
   	The number of Impala HiveServer2 client connections exceeds the threshold	The number of Impala HiveServer2 client connections has been greater than or equal to m	Adjust the value of `fs_sevice_threads` in the `impalad.flgs` configuration in the console	m=64,t=120	Severe	Yes	Yes
   PrestoSQL	The current number of failed PrestoSQL nodes exceeds the threshold continuously	The current number of failed PrestoSQL nodes has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Troubleshoot	m=1, t=1800	Severe	Yes	Yes
   	The number of queuing resources in the current PrestoSQL resource group exceeds the threshold continuously	The number of queuing tasks in the PrestoSQL resource group has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Fine-tune the parameter settings	m=5000, t=1800	Severe	Yes	Yes
   	The number of failed PrestoSQL queries exceeds the threshold	The number of failed PrestoSQL queries is greater than or equal to m	Troubleshoot	m=1, t=1800	Severe	Yes	No
   	A full GC event occurred in a PrestoSQLCoordinator	A full GC event occurred in a PrestoSQLCoordinator	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The PrestoSQLCoordinator JVM memory utilization exceeds the threshold continuously	The PrestoSQLCoordinator JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the PrestoSQLCoordinator heap memory size	m=0.85, t=1800	Severe	Yes	Yes
   	A full GC event occurred on a PrestoSQL worker	A full GC event occurred on a PrestoSQL worker	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The PrestoSQLWorker JVM memory utilization exceeds the threshold continuously	The PrestoSQLWorker JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the PrestoSQLWorker heap memory size	m=0.85, t=1800	Severe	Yes	No
   Presto	The current number of failed Presto nodes exceeds the threshold continuously	The current number of failed Presto nodes has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Troubleshoot	m=1, t=1800	Severe	Yes	Yes
   	The number of queuing resources in the current Presto resource group exceeds the threshold continuously	The number of queuing tasks in the Presto resource group has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Fine-tune the parameter settings	m=5000, t=1800	Severe	Yes	Yes
   	The number of failed Presto queries exceeds the threshold	The number of failed Presto queries is greater than or equal to m	Troubleshoot	m=1, t=1800	Severe	Yes	No
   	A full GC event occurred on a PrestoSQL coordinator	A full GC event occurred on a PrestoSQL coordinator	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The Presto coordinator JVM memory utilization exceeds the threshold continuously	The Presto coordinator JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the Presto coordinator heap memory size	m=0.85, t=1800	Moderate	Yes	Yes
   	A full GC event occurred on a Presto worker	A full GC event occurred on a Presto worker	Fine-tune the parameter settings	-	Moderate	Yes	No
   	The Presto worker JVM memory utilization exceeds the threshold continuously	The Presto worker JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the Presto worker heap memory size	m=0.85, t=1800	Severe	Yes	No
   Alluxio	The current total number of Alluxio workers is below the threshold continuously	The current total number of Alluxio workers has been smaller than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Troubleshoot	m=1, t=1800	Severe	Yes	No
   	The utilization of the capacity on all tiers of the current Alluxio worker exceeds the threshold	The utilization of the capacity on all tiers of the current Alluxio worker has been greater than or equal to the threshold for t (300 ≤ t ≤ 604,800) seconds continuously	Fine-tune the parameter settings	m=0.85, t=1800	Severe	Yes	No
   	A full GC event occurred on an Alluxio master	A full GC event occurred on an Alluxio master	Troubleshoot	-	Moderate	Yes	No
   	The Alluxio master JVM memory utilization exceeds the threshold continuously	The Alluxio master JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the Alluxio worker heap memory size	m=0.85, t=1800	Severe	Yes	Yes
   	A full GC event occurred on an Alluxio worker	A full GC event occurred on an Alluxio worker	Troubleshoot	-	Moderate	Yes	No
   	The Alluxio worker JVM memory utilization exceeds the threshold continuously	The Alluxio worker JVM memory utilization has been greater than or equal to m for t (300 ≤ t ≤ 604,800) seconds continuously	Adjust the Alluxio master heap memory size	m=0.85, t=1800	Severe	Yes	Yes
   Kudu	The cluster replica skew exceeds the threshold	The cluster replica skew has been greater than or equal to the threshold for t (300 ≤ t ≤ 3,600) seconds continuously	Run the `rebalance` command to balance the replicas	m=100, t=300	Moderate	Yes	Yes
   	The hybrid clock error exceeds the threshold	The hybrid clock error has been greater than or equal to the threshold for t (300 ≤ t ≤ 3,600) seconds continuously	Make sure that the NTP daemon is running and the network communication with the NTP server is normal	m=5000000, t=300	Moderate	Yes	Yes
   	The number of running tablets exceeds the threshold	The number of running tablets has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Too many tablets on a node can affect the performance. We recommend you clear unnecessary tables and partitions or expand the capacity as needed	m=1000, t=300	Moderate	Yes	Yes
   	The number of failed tablets exceeds the threshold	The number of failed tablets has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Check whether any disk is unavailable or data file is corrupted	m=1, t=300	Moderate	Yes	Yes
   	The number of failed data directories exceeds the threshold	The number of failed data directories has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Check whether the path configured in the `fs_data_dirs` parameter is available	m=1, t=300	Severe	Yes	Yes
   	The number of full data directories exceeds the threshold	The number of full data directories has been greater than or equal to m for t (120 ≤ t ≤ 3,600) seconds continuously	Clear unnecessary data files or expand the capacity as needed	m=1, t=120	Severe	Yes	Yes
   	The number of write requests rejected due to queue overloading exceeds the threshold	The number of write requests rejected due to queue overloading has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Check whether the number of write hotspots or worker threads is small	m=10, t=300	Moderate	Yes	No
   	The number of expired scanners exceeds the threshold	The number of expired scanners has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Be sure to call the method for closing a scanner after reading data	m=100, t=300	Moderate	Yes	Yes
   	The number of error logs exceeds the threshold	The number of error logs has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Troubleshoot	m=10, t=300	Moderate	Yes	Yes
   	The number of RPC requests that timed out while waiting in the queue exceeds the threshold	The number of RPC requests that timed out while waiting in the queue has been greater than or equal to m for t (300 ≤ t ≤ 3,600) seconds continuously	Check whether the system load is too high	m=100, t=300	Moderate	Yes	Yes