Mongodb Copy Data From One Collection To Another

Serendip is a social music service, used as a http://www.aliyun.com/zixun/aggregation/10585.html "> Music sharing" between friends. Based on the "people to clustering" this reason, users have a great chance to find their favorite music friends. Serendip is built on AWS, using a stack that includes Scala (and some Java), Akka (for concurrency), play framework (for Web and API front-end ...).

Serendip is a social music service, used as a http://www.aliyun.com/zixun/aggregation/10585.html "> Music sharing" between friends. Based on the "people to clustering" this reason, users have a great chance to find their favorite music friends. Serendip is built on AWS, using a stack that includes Scala (and some Java), Akka (for concurrency), play framework (for Web and API front-end ...).

This usage is very practical for the following applications: write-intensive cache embedded systems that precede a slow RDBMS system require a lightweight database and a unit test that data in the library can easily be purged without the need for a persistent data-compliant PCI system (testing) If all this could be done, it would be elegant: we would be able to manipulate http://www.aliyun.com/zixun/aggregati without involving disk operations ...

In mailbox rapid expansion process, one of the performance problems is the MongoDB database level write lock, the time spent in the lock waiting process, directly reflects the user's use of the service process delay. To address this long-standing problem, we decided to migrate a common set of MongoDB (storing mail-related data) to a separate cluster. According to our inference, this will reduce the lock latency by 50%, and we can add more fragments, and we expect to be able to optimize and manage different types of data independently. We start from Mon ...

As a http://www.aliyun.com/zixun/aggregation/6434.html "> software developer, we value the abstraction of things." The simpler the API, the more attractive it is to us. 　　Dialectically, the biggest advantage of MongoDB is the "elegant" API and its agility, which makes the coding process of developers unusually simple. However, when MongoDB involves large data scalability issues, developers still need to know the bottom of it ...

There are a few things to explain about prismatic first. Their entrepreneurial team is small, consisting of just 4 computer scientists, three of them young Stanford and Dr. Berkeley. They are using wisdom to solve the problem of information overload, but these PhDs also act as programmers: developing Web sites, iOS programs, large data, and background programs for machine learning needs. The bright spot of the prismatic system architecture is to solve the problem of social media streaming in real time with machine learning. Because of the trade secret reason, he did not disclose their machine ...

"Editor's note" WiX has been operating the site for a long time, and after the launch of the WYSIWYG web platform based on HTML5, users have established more than 54 million sites in the company, and most of these sites have less than 100 solar PV. Since the PV of each page is low, the traditional caching strategy does not apply. Even so, however, the company has done so with only 4 Web servers. Recently, WiX chief back-end engineer Aviran Mordo in "...

This article is my second time reading Hadoop 0.20.2 notes, encountered many problems in the reading process, and ultimately through a variety of ways to solve most of the. 　　Hadoop the whole system is well designed, the source code is worth learning distributed students read, will be all notes one by one post, hope to facilitate reading Hadoop source code, less detours. 1 serialization core Technology The objectwritable in 0.20.2 version Hadoop supports the following types of data format serialization: Data type examples say ...

TA (Tencent Analytics), a free website analysis system for third-party webmasters, is highly praised by webmasters for data stability and timeliness, and its second-level real-time data update frequency is also recognized by the industry. This article will take you in-depth exploration of TA system architecture and implementation principles from many aspects of real-time data processing, data storage and so on. Web Analytics (Web Analytics) mainly refers to the site-based ...

Malware analysis, penetration testing, and computer forensics - GitHub hosts a host of compelling security tools that address the real needs of computing environments of all sizes. As the cornerstone of open source development, "all holes are superficial" has become a well-known principle or even a credo. As widely known as Linus's law, the theory that open code can improve the efficiency of project vulnerability detection is also widely accepted by IT professionals when discussing the security benefits of the open source model. Now, with the popularity of GitHub ...