ACA-Developer Exam Dumps - ACA Developer Certification

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.

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

Custom Events are used for collection of continuous event type data, queries, and alarms.

Custom Events is for periodic and continuous collection of time series monitoring data, queries, and alarms.

Custom Monitoring is used for periodic and continuous collection of time series monitoring data, queries, and alarms.

Custom Monitoring is used for collection of non-continuous event data, such as information about ECS instance restarts.

The log project (Project) does not exist

The requested digital signature does not match

Server internal error

Server is busy: please try later

A snapshot is a backup file of the cloud disk data state at a certain point in time. The first snapshot of the cloud disk is a full snapshot of the ac usage. Empty data blocks are not backed up. All subsequent snapshots are incremental snapshots, and only changed data blocks are stored.

Snapshots can be created manually through the web console or command line tools, or automatically according to a schedule.

In the event of a system failure, you can use a snapshot to roll back the Cloud Disk to an earlier point in time.

Snapshot rollbacks can be performed while the ECS instance is running.

Make sure that the security group of the ECS instance allows outbound access to the MySQL service port.

Add the private and public IP addresses of all applications to the RDS whitelist.

Connect the two VPCs through CEN.

Configure a NAT gateway for the VPC to which the ECS instance belongs.

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The function has a shared state and cannot be accessed concurrently.

Requests are waiting for responses from the downstream service for an extended period of time.

A request consumes a large amount of CPU and memory resources.

Functions processes independent data objects.

HTTP(s) service

CloudMonitor Service

Resources In a VPC

Function Compute

Log service

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A visitor's real IP address can only be obtained by modifying the site or web application.

A visitor's real IP address is stored in the "X-Forwarded-For" HTTP header It can be directly obtained via Apache or NGINX logs.

In Windows, if IIS is used, after installing the "F5XForwardedFor" extension module, the visitor's real IP address can be seen via IIS logs.

You can activate the "record visitor's real IP" function in the Alibaba Cloud CDN console, then you can directly view visitor's IP addresses from the Alibaba Cloud CDN access logs.