AnalyticDB MySQL for MySQL resource group supports Multi Cluster elastic model_Cloud native data warehouse AnalyticDB MySQL version (AnalyticDB for MySQL)

Cloud native data warehouse AnalyticDB MySQL Hucang version (3.0) Resource groups support the multi cluster elastic model. You can enable the multi cluster function when creating interactive resource groups. The multi cluster elastic model consists of one or more clusters. It can automatically expand and shrink resources according to the business load to meet the resource isolation and high concurrency scenarios within the resource group.

prerequisite

Hucang version (3.0) The kernel version of the cluster must be 3.1.10.0 or higher.

explain To view the cluster kernel version, see How to view instance version information 。 If you need to upgrade the kernel version, please contact technical support.

What is a Multi Cluster resource group

When the Multi Cluster function is not enabled, only one cluster in a resource group executes queries. When the query task is submitted to the resource group, these queries share all the computing resources of the resource group and start executing the query. If there are too many queries running in the resource group, resource contention will occur, affecting the query speed. If the query concurrency of the resource group reaches the upper limit, queries will be queued.

Multi cluster resource group is composed of one or more clusters. Users can apply for cluster resources statically or dynamically to cope with changing loads. After the user queries the different cluster computing assigned to the resource group through the access node, each cluster can query independently without affecting each other. As shown in the figure below.

Multi Cluster resource group is suitable for improving the concurrency of small and medium-sized queries and reducing the resource contention problem of queries, but it will not improve the speed of slow queries and ETL tasks.

matters needing attention

The Multi Cluster model only applies to Interactive resource groups.
The resource group created before kernel version 3.1.10.0 does not support direct upgrade to MultiCluster mode. You need to create a new Interactive resource group after upgrading the cluster kernel version, and then enable the Multi Cluster function.
The same Interactive resource group does not support the simultaneous activation of resource elastic planning and multi cluster functions.

Advantages of Multi Cluster

For resource groups without Multi Cluster mode enabled, when the query load continues to grow until the computing resources of the resource group cannot meet the business needs, you need to manually perform the following operations:

Adjust the size of the resource group to meet business needs, or allocate some queries to the rest of the resource groups to reduce the computing pressure of the current resource group.
When resource contention occurs between large query and small query, which affects the response speed of small query, you need to manually send the large query to the Job type resource group.
When the query load drops and the computing resources of the resource group are redundant, you need to shrink the computing resource group to save costs.

For resource groups with Multi Cluster mode enabled, multiple clusters with the same resource size can be connected in the system to execute queries in the same resource group. It will bring you the following advantages:

In elastic mode, you no longer need to manually adjust the size of resource groups to handle the jittery query load, AnalyticDB for MySQL It will automatically help you adjust the number of clusters according to the query load.
In the maximum mode, you can control the total amount of computing resources in the resource group by adjusting the number of clusters.
Clusters within a resource group are isolated from each other. Large queries only affect the cluster where they are located. Queries in other clusters work normally.

Expense description

After Multi Cluster is enabled, the resources consumed will be Hucang version (3.0) Calculate reserved resources and Elastic resources Is charged. For details, see Hucang version (3.0) product pricing 。

Computing reserved resources: computing reserved resources purchased during cluster creation.
Elastic resources: resources corresponding to the number of clusters that pop up in the resource group. The calculation method is Total resources used - calculate reserved resources 。

open Multi Cluster function

Sign in Cloud native data warehouse AnalyticDB MySQL console , select the cluster region in the upper left corner. On the left navigation bar, click Cluster List , on Hucang version (3.0) Tab, click the target cluster ID.
On the left navigation bar, click Cluster management > resource management , click Resource group management Tab.

Click the New resource group , and fill in the resource group information.

explain

When using the Multi Cluster function, it is recommended to start from the elastic mode and set an appropriate Cluster size ， According to the size of reserved resources Adjust the appropriate concurrent number At the same time, set the maximum number of clusters smaller (for example, the maximum number of clusters is 3, and the minimum number of clusters is 1). Then you can adjust it step by step according to the actual fluctuation of the load Cluster size And the number of clusters until your requirements are met.

Parameter name	explain
Resource group name	The name of the custom resource group. The input length is 2~30 digits, starting with a letter, and can only contain letters, numbers, and underscores.
Task Type	Interactive 。 The Multi Cluster model only applies to Interactive resource groups.
Cluster size	The size of a single cluster, that is, the number of ACUs, can be filled in at will, with a minimum of 16 ACUs. explain Cluster size Not accepted Hucang version (3.0) Calculate the limit of reserved resources, if Cluster size If it is greater than the reserved resources calculated, the excess will be calculated according to Elastic resources Billing. For details, see Hucang version (3.0) product pricing 。
Open Multi Cluster	Turn on the switch.
pattern	Hucang version (3.0) The Multi Cluster resource group provides the following two modes. Elastic mode : Set different Minimum number of clusters and Maximum number of clusters , by AnalyticDB for MySQL According to the query load of the user resource group, the cluster Minimum number of clusters and Maximum number of clusters And dynamically expand and shrink the capacity. The initial number of clusters in the resource group is equal to Minimum number of clusters 。 When the resources are insufficient, the user queries begin to queue or AnalyticDB for MySQL When it is judged that the existing computing resources cannot meet the current load, the number of clusters will increase until Maximum number of clusters 。 When the load of the resource group decreases, AnalyticDB for MySQL When it is judged that the current load of existing resources is redundant, the number of clusters will decrease until Minimum number of clusters 。 Maximum mode : Specify the same Minimum number of clusters and Maximum number of clusters , the number of clusters must be greater than or equal to 2. In the maximum value mode, the specified number of clusters will be started after the resource group is successfully created. This mode can effectively and statically control the total amount of computing resources in the resource group, and is suitable for scenarios where the concurrent number of user queries is relatively stable and there is no obvious jitter.
Minimum number of clusters	At least the number of clusters in the resource group needs to be maintained. It needs to be less than or equal to the maximum number of clusters. The minimum number is 1.
Maximum number of clusters	The maximum number of clusters that can be expanded to is 10.

single click determine , enable the Multi Cluster function.
After the Multi Cluster function is enabled, Resource group management The tab allows you to view the minimum, maximum and running number of multi cluster resource groups operation Column monitor You can also view detailed resource group related indicators in the option.

Appendix: Multi Cluster Capacity Expansion Description

When you expand and shrink the multi cluster, the number of clusters in the resource group changes as follows.

Elastic mode

Maximum number of clusters to be expanded : Increase the maximum number of clusters. The current number of clusters will not change until the load meets the capacity expansion requirements.
Maximum number of clusters to shrink: If the number of clusters running at this time is greater than the maximum number of clusters after resizing, the new query will not be sent to the redundant cluster. After the query on the redundant cluster is completed, the cluster will be resized.
Minimum number of clusters for capacity expansion : A new cluster is created immediately until the specified minimum number of clusters is met.
Minimum number of clusters to shrink : If the number of running clusters is greater than the minimum number of clusters after resizing, AnalyticDB for MySQL It will continuously monitor your query load within the five minute time window, and will not shrink to the minimum number of clusters you configured until your load meets the shrink condition.

Maximum mode

Maximum number of clusters for capacity expansion&minimum number of clusters : Directly expand the number of clusters to the maximum number you set.
Shrink the maximum number of clusters&minimum number of clusters : The new query will not be sent to the redundant cluster. After the query on the redundant cluster is completed, the cluster will be shrunk.