Cache penetration means that malicious users continuously query data that does not exist in the database, resulting in performance degradation. Solutions include: setting default values, using bloom filters, using verification code mechanisms to limit traffic, slow query log analysis, and strengthening data verification
Redis cache traversal Penetration solution
#What is cache penetration?
Cache penetration means that malicious users or crawlers continuously query data that does not exist in the database, resulting in a large number of database queries and performance degradation.
Solution:
1. Set default value:
For non-existent data, you can set a default value , such as null values or error messages, and cache them. When the user queries the data, the default value in the cache is returned directly to avoid database queries.
2. Bloom filter:
The Bloom filter is a probabilistic data structure that can quickly determine whether an element is in a set. In the cache penetration scenario, all possible data queries can be converted into keys in the Bloom filter. When the user queries for non-existent data, the Bloom filter returns negative results and directly returns null values or error messages to avoid Database query.
3. Verification code mechanism:
For high-frequency malicious requests, the verification code mechanism can be used to filter. When users query a large amount of non-existent data, they are required to provide a verification code to verify their identity and prevent malicious attacks.
4. Current limiting:
For specific users or IP addresses, you can set request current limiting. When it exceeds a certain threshold, an error message will be returned directly to avoid database queries. .
5. Slow query log analysis:
By analyzing the slow query log, find out the requests that frequently query non-existent data, and optimize or repair them accordingly.
6. Strengthen data verification:
Verify the input data at the application code layer to ensure that non-existent data will not be queried. For example, determine whether the ID is a positive integer, whether the timestamp is within a reasonable range, etc.
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