Configure parameters when you purchase an Alibaba Cloud Elasticsearch cluster - Elasticsearch

This topic describes the functions of each node type in an Alibaba Cloud Elasticsearch cluster and guides you through configuring node-related parameters during purchase.

Data nodes

Data nodes store indexes and handle tasks such as adding, removing, modifying, searching, and aggregating documents. These nodes require significant CPU, memory, and I/O capabilities. To enhance cluster performance, monitor the data nodes' statuses regularly. If the cluster's resources are insufficient, consider adding more data nodes.

Note

Data nodes serve exclusively as data nodes if dedicated master nodes are purchased.
Without dedicated master nodes, data nodes also function as dedicated master nodes.
Scaling out an Elasticsearch cluster with the old architecture (v2) without dedicated master nodes will trigger a restart. The new architecture (v3) eliminates the need for a restart. If the cluster's overall load is low and replica shards are present, the cluster can continue to operate during the restart. However, access may time out during the restart in certain scenarios, such as during heavy write and query operations or a forced restart. It's best to perform this operation during off-peak hours.

Parameter	Description
Data Node Specifications	2 vCPUs and 4 GiB specifications instances are recommended for use in test environments. In production environments, we recommend that you use higher specifications.
Data Node Storage Type	ESSD (default): Provides low latency, quick response, and high data throughput. ESSD is suitable for latency-sensitive applications or I/O-intensive business scenarios. For more information about ESSD specifications, see Node specifications. For more information about ESSD performance, see ESSD. Ultra Disk: Provides cost-effective storage capabilities. Ultra disk is suitable for scenarios in which a large amount of data needs to be logged or analyzed. Standard SSD: Suitable for online analysis and search scenarios that require high IOPS and high data responsiveness. Note You can view the supported disk types on the buy page. After a cluster is created, you cannot change the disk types of nodes in the cluster.
Data Node Storage Performance Level	If you set the Data Node Disk Type parameter to ESSD, you need to configure this parameter.
Data Node Disk Encryption	Disk encryption offers the maximum data security without requiring you to make additional changes to your businesses and applications. However, disk encryption may have a small impact on the performance of your cluster. Disk encryption is free of charge. No additional fees are generated when you read data from or write data to encrypted disks. Note You cannot disable disk encryption for encrypted disks. You cannot enable disk encryption for purchased disks. When you upgrade the configuration of a cluster, you cannot enable disk encryption for purchased disks. If you purchase cloud disks when you upgrade the configuration of the cluster, you can enable disk encryption.
Storage Space Of Each Data Node	The storage space of each data node depends on the disk type. ESSD: The maximum storage space is 6 TiB. Ultra Disk: The maximum storage space is 20 TiB for instances of versions 6.7, 7.7, and later. The maximum storage space is 5 TiB for instances of other versions. Standard SSD: The maximum storage space is 6 TiB for instances of versions 6.7, 7.7, and later. The maximum storage space is 2 TiB for instances of other versions. Note An ultra disk with a storage space greater than 2 TiB is designed to run in disk arrays or RAID 0. When you resize the ultra disk, only a blue-green update can be performed for the ultra disk.
Number Of Data Nodes	The number of data nodes that you purchase must be a multiple of the number of zones. Important If a cluster is configured with only two data nodes, the cluster may encounter split-brain issues. In low-version clusters, such as 6.x and 5.x, the cluster may fail to elect a primary node when a change that requires a node restart occurs. This may cause service unavailability and low stability. Exercise caution when you configure the cluster in production environments.

Kibana nodes

The Kibana Node parameter can only be set to Yes.
A Kibana node with 1 vCPU and 2 GiB of memory is provided free of charge but is recommended only for testing purposes.
For improved cluster performance and stability, consider purchasing a Kibana node with at least 2 vCPUs and 4 GiB of memory.

Dedicated master nodes

Dedicated master nodes manage cluster operations such as creating and deleting indexes, tracking nodes, and allocating shards. Their stability is crucial for cluster health. By default, any node can act as a dedicated master node. However, to ensure cluster stability, it is advisable to purchase dedicated master nodes to separate them from data nodes, especially since operations like data indexing and queries consume extensive CPU, memory, and I/O resources.

Important

You will incur charges for dedicated master nodes after upgrading your cluster's configuration, even if they were initially free.
Using the basic control (V2), an update without dedicated master nodes will cause data nodes to restart during the next update. Purchasing dedicated master nodes is recommended to avoid this.

Parameter	Description
Dedicated Master Nodes	To improve the stability of your services, we recommend that you purchase dedicated master nodes. For a multi-zone Elasticsearch cluster, the default value of this parameter is Yes, and you cannot change the value. Note You cannot release the dedicated master nodes that you have purchased. After a cluster is created, you can purchase dedicated master nodes when you upgrade the configuration of the cluster.
Dedicated Master Node Specifications	You can view the supported specifications on the buy page.
Dedicated Master Node Storage Type	ESSD (default): Provides low latency, quick response, and high data throughput. ESSD is suitable for latency-sensitive applications or I/O-intensive business scenarios. For more information about ESSD specifications, see Node specifications. For more information about ESSD performance, see ESSD. Ultra Disk: Provides cost-effective storage capabilities. Ultra disk is suitable for scenarios in which a large amount of data needs to be logged or analyzed. Standard SSD: Suitable for online analysis and search scenarios that require high IOPS and high data responsiveness. You can view the supported disk types on the buy page.
Dedicated Master Node Storage Space	The value of this parameter can be only 20G.
Number Of Dedicated Master Nodes	The value of this parameter can be only 3.

Warm nodes

If your business involves both frequently and infrequently queried or written indexes, purchasing warm nodes to implement a hot-warm architecture is recommended. This approach enhances processing performance and cluster service stability.

Indexes that are frequently queried or written to.
Indexes that are infrequently queried or written to, typically historical records.

For more information, see Elasticsearch Hot Warm Architecture.

Note

Warm nodes are exclusively used as warm nodes if dedicated master nodes are purchased.

Without dedicated master nodes, warm nodes also serve as dedicated master nodes.

Parameter	Description
Warm Nodes	You cannot release the warm nodes that you have purchased.
Warm Node Specifications	You can view the supported specifications on the buy page.
Warm Node Storage Type	The value of this parameter can be only Ultra Disk.
Warm Node Disk Encryption	Disk encryption offers the maximum data security without requiring you to make additional changes to your businesses and applications. However, disk encryption may have a small impact on the performance of your cluster. Disk encryption is free of charge. No additional fees are generated when you read data from or write data to encrypted disks. Note You cannot disable disk encryption for encrypted disks. You cannot enable disk encryption for purchased disks. When you upgrade the configuration of a cluster, you cannot enable disk encryption for purchased disks. If you purchase cloud disks when you upgrade the configuration of the cluster, you can enable disk encryption.
Warm Node Storage Space	The minimum value of this parameter is 500. Unit: GiB.
Number Of Warm Nodes	The number of warm nodes that you purchase must be a multiple of the number of zones.

Upon purchasing warm nodes, the system adds -Enode.attr.box_type to the startup parameters of the nodes, as detailed in the following table.

Node type	Startup parameter
Data node	-Enode.attr.box_type=hot
Warm node	-Enode.attr.box_type=warm

Client nodes

Client nodes can be purchased to distribute the CPU load of data nodes, thereby improving the processing performance and stability of a cluster. They are particularly recommended for CPU-intensive services, such as those requiring numerous aggregate queries.

Parameter	Description
Client Nodes	For instances that are deployed based on the cloud-native control architecture (versions 7.16 and later ), you cannot release the client nodes that you have purchased. The actual specifications are subject to those on the buy page.
Client Node Specifications	You can view the supported specifications on the buy page.
Client Node Storage Type	The value of this parameter can be only Ultra Disk.
Client Node Storage Space	The value of this parameter can be only 20G.
Number Of Client Nodes	The number of client nodes that you purchase must be a multiple of the number of zones.

References

For more information on purchasing an Elasticsearch cluster, see Create an Alibaba Cloud Elasticsearch cluster.
For the official documentation on each node, see Node | Elasticsearch Guide.
For pricing details of each node specification, see or Pricing.