Tag:Persistence

  • Redis’s persistence scheme

    Time:2020-5-20

    Redis supports two persistence mechanisms, RDB and AOF. Persistence can avoid data loss caused by abnormal process exit or down machine. In the next restart, the previous persistence file can be used to recover data. RDB persistence RDB persistence is to create a snapshot (compressed binary) to persist, saving the full amount of data at […]

  • Simple use of MySQL transaction

    Time:2020-4-9

    4 characteristics Atomicity: all operations in a transaction are either completed or not, and will not end at a certain link in the middle. If an error occurs during the execution of a transaction, it will be rolled back to the state before the transaction starts Consistency: before and after the transaction, the integrity of […]

  • Redis tutorial (10): details of persistence

    Time:2020-2-21

    1、 What persistence mechanisms redis provides: 1). RDB persistence:This mechanism is to write the data set snapshot in memory to disk within a specified time interval.    2). AOF persistence:This mechanism will record every write operation processed by the server in the form of log. At the beginning of redis server startup, the file will be […]

  • Meet coredata – get to know coredata

    Time:2020-2-15

    This article belongs to the original of “Jianshu Liu Xiaozhuang”. Please indicate: < Jianshu Liu Xiaozhuang > http://www.jianshu.com/p/c0e12a897971 `During this period, the company has been relatively busy, and together with the small partners in the group, the company’s project has been rewritten according to the previous logic. Because the project is relatively large, and the […]

  • Understanding coredata – using advanced

    Time:2020-2-13

    This article belongs to the original of “Jianshu Liu Xiaozhuang”. Please indicate: < Jianshu Liu Xiaozhuang > http://www.jianshu.com/p/a4710356244d The previous two articles are more theoretical, more text expression, but are dry goods! When learning, we should understand the theoretical knowledge first, so as to better help the later understanding. In this article, we will talk […]

  • Understanding coredata – advanced usage

    Time:2020-2-12

    This article belongs to the original of “Jianshu Liu Xiaozhuang”. Please indicate: < Jianshu Liu Xiaozhuang > http://www.jianshu.com/p/01f36026da7d In the previous articles, I have talked a lot aboutCoreDataUse relevant knowledge points. This article focuses on two aspects,NSFetchedResultsControllerAnd version migration. Although there are“Advanced”In fact, the two words are not advanced, just because there are too many […]

  • Redis persistent RDB

    Time:2019-12-3

    I. what is it Write the data set snapshot in memory to disk within the specified time, that is, snapshot snapshot. When it recovers, it reads the snapshot file directly into memory.Redis will create (fork) a subprocess for persistence. It will write the data to a temporary file first, and then replace the last persistent […]

  • Redis persistent AOF

    Time:2019-12-2

    I. what is it Log each write as a log, record all the write instructions executed by redis (no record of read operation), only add files but not write files. At the beginning of redis startup, it will read the file and rebuild the data. In other words, when redis restarts, it will execute the […]

  • Install permanent virtual memory on the Ubuntu server system

    Time:2019-9-14

    Virtual memory, when installing Linux system locally, we usually divide up separate swap partitions in advance.Usually, however, cloud servers don’t allocate virtual memory to you when you reinstall your system.And the physical memory of cloud servers is too expensive. It can be said that it can hardly live without virtual memory.I had this problem the […]

  • IOS key-value persistence components with high performance and real-time performance

    Time:2019-8-26

    In the first half of this year, I saw an article by the development team of Wechat, MMKV, a high-performance universal key-value component of iOS based on mmap. It mentioned how to implement a high-performance KV component with mmap. Although it did not show too much specific code, the basic idea is clear.At the end […]

  • Summary of Redis Persistence in Memory Database

    Time:2019-7-27

    Because Redis is an in-memory database, in order to prevent data loss caused by system crash, Redis provides two different persistence methods to store data in hard disk. One is snapshot (RDB), which can write all data that exists at a certain time to hard disk. Another method is to append only files (AOF), which […]

  • Problems in the use of redis and how to avoid them (1)

    Time:2019-7-24

    Redis can satisfy many application scenarios, and because all data is stored in memory, it has good read and write performance, many companies are using redis. Redis brings us convenience, but at the same time, what problems will exist in the use process? This article will briefly summarize. Blocking problemRedis uses a single thread to […]