• Why Apache bookkeeper? (Part 1)


    Original author: Sijie GuoTranslation: streamnnative Sijia Apache bookkeeper is optimized for real-time workload and is a scalable, fault-tolerant, low latency log storage service. Initially developed by Yahoo! Research, bookkeeper was incubated as a sub project of Apache zookeeper in 2011, and finally launched as a top-level project of Apache in January 2015. Since its initial […]

  • Mysql database (2) transaction


    InnoDB, MySQL’s storage engine, supports transactions. MyISAM does not support transactions Four characteristics of database transaction (acid) Atomicity (atomic)  Atomicity refers to the fact that all operations contained in a transaction are either successful or fail to roll back. This is the same concept as the functions of Transactions described in the previous two blogs. Therefore, […]

  • Redis’s persistence scheme


    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


    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


    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


    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


    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


    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


    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


    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


    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


    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 […]