Alibaba Cloud ACA-Developer ACA Developer Certification Exam Practice Test

The primary database (the one to be backed up) must have an Alibaba Cloud Intranet address

RDS realizes real-time synchronization between the master instance and the remote disaster recovery instance through Data Transmission Service (DTS)

When an outage occurs in the area where the primary instance is located, and neither the primary instance (Master) nor the standby instance (Slave) can be connected to, the remote disaster recovery instance can be switched to the primary instance

When the database deletion operation is performed on the master instance, the operation will also be synchronized to the disaster recovery instance

The security group for ECS-A does not have the default MySQL service port open.

The built-in firewall on ECS-A has rules that prohibit external access to the MySQL service port.

No Internet IP address is configured for ECS-A.

The bind-address parameter set in the my.ini configuration file of the MySQL service is commented out.

Alibaba Cloud provides a wealth of block storage products for ECS, including Cloud Disks (virtualized storage) and Local Disks (physically attached to the server(s) that host your ECS Instances).

Both Local Disks and Cloud Disks use a multi-copy distributed storage mechanism, which has low latency, high performance, durability, and high reliability, and supports creation, expansion and release at any time.

Cloud Disks come In several different varieties: ESSD (Enhanced Solid State) Cloud Disks. SSD (Solid State ) Cloud Disks, and high-efficiency Cloud Disks.

Two types of Cloud Disks can be attached to an ECS: System Disks and Data Disks. System Disks host the ECS instances operating system.

Use a third-party image creation tool to create an image from the physical server. Upload the image to the ECS console to turn it into a custom image. Then, use the custom image to create ECS instances.

Use SMC(Server Migration Center) to collect data from the origin physical server. Create an intermediate ECS instance on Alibaba Cloud and wait for the data transfer to complete. Then generate a new image directly from that intermediate ECS instance.

Use a third-party image creation tool to create an image from the physical server. The image is then uploaded to Alibaba Cloud Object Storage Service (OSS) for storage. In the ECS console, import that image from OSS, then, create an ECS instance from the custom image.

Rejected

Executing

Failed

Timeout

Improve the query efficiency SELECT statements.

Improve the efficiency of DML operations such as UPDATE.

Improve the efficiency of DDL operations.

Reduce invalid data scanning.

PendingDeletion

Pendinglmport

Disabled

PendingCreate

HTTP(S)

TCP/UDP

DNS

SNMP

Function Compute

Object Storage Service (OSS)

Table Store

Log service

Event Notifications can cross regions.

Message Service provides synchronous notifications to ensure the consistency between the message acknowledgment and event processing.

The event notification message is retained within the valid time. When you fail to receive an event message, the event notification message is retried based on the specified retry policy.

The consumer type of the event notification message can be HTTP Server, Queue, or Topic.

Create a b-tree index on each column to be searched.

Create a hash index on each column to be searched.

Create a gin index for multiple fields.

Create a gist index for multiple fields.

Region name

Zone name

Bucket name

Filename

When the user's request enters the system, a globally unique traceld will be generated on the first layer of the calling network.

The tracelD will be called with each layer and passed back continuously, so through traceld, the path of a user request in the system can be connected in series.

Spanld can locate the position of a request in the system call, and who its upstream and downstream dependencies are respectively.

Traceld is used to distinguish the sequence of calls between different services of the system, spanld is used to concatenate all the paths that a certain request traverses in the system.

Low maintenance, low costs

Startup in seconds without the need to reserve resources

Less significant visualization layer performance losses

Stronger isolation between instances