Aliyun Cloud Important Points

There are two versions available for aliyun cli

• CLI Go Version
• CLI Python Version

Make sure Go Version is to be installed as python version is going to be deprecated.

You can refer to the below link for the Aliyun Cli installation

https://github.com/aliyun/aliyun-cli?spm=a2c63.p38356.a3.1.17414388la2EgQ

You can generate the Access key in the Aliyun as follows

Go to Aliyun Console > Resource Access Manager ; Users ; Click on Specific user ; Create Access Key

Save the files (having access keys/Secret Keys) on local machine

#aliyun configure

Currently Aliyun has some Limitation which might be overcome in future

1. Loan Balancers are not elastic.

2. Object storage service similar to what we have s3 in aws does not provide versioning of objects.

EIP in the aliyun can be binded to the ECS, SLB and NAT gateway and max bandwidth can be upto 200Mbps which is configurable.

Almost all major services are available in the Aliyun similar to the AWS Cloud, the also have spot instances like in AWS which are called preemptible instance in alicloud and ECS bare metal servers are also there.

It provides guaranteed performance instances that is opposite to shared performance instances.

There are three key performance metrics for guaranteed performance instances -

1. Max Connection
2. Connection per second
3. Query per second

Following capacities are available:

Type	Specification	Max Connection	CPS	QPS
Specification 1	Small I (slb.s1.small)	5,000	3,000	1,000
Specification 2	Standard I (slb.s2.small)	50,000	5,000	5,000
Specification 3	Standard II (slb.s2.medium)	100,000	10,000	10,000
Specification 4	Higher I (slb.s3.small)	200,000	20,000	20,000
Specification 5	Higher II (slb.s3.medium)	500,000	50,000	30,000
Specification 6	Super I (slb.s3.large)	1,000,000	100,000	50,000

Features: 

• Supported protocol: layer 4 (TCP and UDP), layer 7 (HTTP and HTTPS) load balancing services.
• Health check
• Session persistence
• Scheduling algorithms: Round robin, Weighted round robin, Weighted least connections, Consistent Hash
• Access controls: Blacklist and whitelist IPs
• Certificate management: SSL offloading for HTTPS 
• Instance type: Internet and Intranet
• Bandwidth control

Types of SLB:

• Internet: Provides an internet IP address.
• Intranet: Provides a private IP address of CIDR block of selected Vswitch and VPC. However, an EIP can be bind to serve internet traffic. (Recommended)

Architecture:

• Layer 4 uses the open source software Linux Virtual Server (LVS) with keepalived to achieve load balancing.
• Layer 7 uses Tengine.

Traffic distribution to Backend server groups:

• VServer group: Different VServer groups can be created to distribute different request to different backend servers. (Recommended)
• Active/standby server group: At most two ECS instances can be added out of which one acts as the active server and other as standby server.
• Default server group: It will be used by default if listener is not configured to use either VServer group or Active/standby server group.

Forwarding rules:

Forwarding rules can be configured for each listener and route traffic to different VServer group based on domain/URL e.g.,

test.com/uri-1 to one backend server group and test.com/uri-2 to another backend server group

About Disks:-

Initiallly Disk can be taken from 20 GB to 32768 GB (32 TB).

IOPS -

20 GB - 2400 IOPS
30 GB - 2700 IOPS
40 GB - 3000 IOPS

As shown above, 300 IOPS is being increased per 10 GB.
Max IOPS 25000 per disk.