CPUCreditBalance stucks on zero

Does someone knows which is the CPU baseline for db.t4g.micro ?

The t4g.micro has a CPU baseline of 10%, you should earn 12 credits per hour if your are below this baseline. You can earn a max of 288 credits, which should be a BurstBalance of 100%. See also [1].

Can you share some screenshots of your RDS CloudWatch monitoring? Just open the RDS instance and switch to the "monitoring" tab. The first page of widgets is important

• CPUUtilization
• BurstBalance
• CPUCreditBalance
  • The number of CPU credits that an instance has accrued. This balance is depleted when the CPU bursts and CPU credits are spent more quickly than they are earned
• CPUCreditUsage
  • The number of CPU credits spent during the measurement period
• CPUSurplusCreditBalance
  • The number of surplus CPU credits spent to sustain CPU utilization when the CPUCreditBalance value is zero.
• CPUSurplusCreditCharged
  • The number of surplus CPU credits exceeding the maximum number of CPU credits that can be earned in a 24-hour period, and thus attracting an additional charge.

The last two metrics apply only to instances configured as unlimited.

[1] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-credits-baseline-concepts.html#earning-CPU-credits