riak

主流NoSQL及应用场景详解

由 南笙酒味 提交于 2020-10-14 13:33:24
点击上方“朱小厮的博客”，选择“设为星标” 后台回复"书"，获取 来源：r6d.cn/r4P7 对比传统关系型数据库，NoSQL有着更为复杂的分类——键值、面向文档、列存储以及图数据库。这里就带你一览NoSQL各种类型的适用场景及一些知名公司的方案选择。 在过去几年，关系型数据库一直是数据持久化的唯一选择，数据工作者考虑的也只是在这些传统数据库中做筛选，比如SQL Server、Oracle或者是MySQL。甚至是做一些默认的选择，比如使用.NET的一般会选择SQL Server；使用Java的可能会偏向Oracle，Ruby是MySQL，Python则是PostgreSQL或MySQL等等。 原因很简单，过去很长一段时间内，关系数据库的健壮性已经在多数应用程序中得到证实。我们可以使用这些传统数据库良好的控制并发操作、事务等等。然而如果传统的关系型数据库一直这么可靠，那么还有NoSQL什么事？NoSQL之所以生存并得到发展，是因为它做到了传统关系型数据库做不到的事！ 关系型数据库中存在的问题 Impedance Mismatch 我们使用Python、Ruby、Java、.Net等语言编写应用程序，这些语言有一个共同的特性——面向对象。但是我们使用MySQL、PostgreSQL、Oracle以及SQL Server，这些数据库同样有一个共同的特性——关系型数据库。这里就牵扯到了

Installed Riak does not have advanced.conf

由 断了今生、忘了曾经 提交于 2020-01-24 21:23:40
问题 I have Riak 2.1.4 installed by deb file in ubuntu. A couple of questions : I dont see advanced.conf file in /etc/riak , where can i locate it ? Anybody has a basic config files for riak.conf and advanced.conf for a 5 node cluster. Please share. i have added security ports in inbound tab of security group i see they cannot communicate. Does it look fine ? Thanks in advance 来源： https://stackoverflow.com/questions/40495788/installed-riak-does-not-have-advanced-conf

Riak node no longer working after changing IP address

由 爷，独闯天下 提交于 2020-01-22 23:03:47
问题 I'm using an instanced Amazon EC2 virtual Ubuntu 12.04 server as my single Riak node. I've gone through all the proper stages of setting up Riak on the instance using the guide on the basho website here . Where x.x.x.x is the private IP address of the instance, this included: Installation Using sudo su - to gain root privileges (EC2 logs me in as 'Ubuntu'). Installing the SSL Lib with: sudo apt-get install libssl0.9.8 Downloading the 64-bit package for 12.04: wget http://downloads.basho.com

How to understand this Riak stacktrace?

由 一个人想着一个人 提交于 2020-01-17 03:51:05
问题 Can anyone help me solve this problem, I have the stacktrace of the problem, but can't understand what the trace actually means. The error occurs when I try to retrieve all data from a bucket, in a Riak Database. And I am using java-riak-client library as the ORM. I can figure out that its a MapReduce problem, but other than that..... Here below is the actual stacktrace, I actually could not figure out what error is it pointing to, and I tried to find out the record its displaying in error.

Memory Requirement/Utilization for MongoDB, Riak and HyperTable (or HBase)

由 雨燕双飞 提交于 2020-01-04 19:47:07
问题 I've evaluated most of the NoSQL solutions and it seems that using a combination of MongoDB, Riak and HyperTable (or HBase) is the way to go. What is the minimum requirement for these databases to run comfortably? Let's say, if I deploy these databases (MongoDB, Riak and HyperTable - or HBase) - and Web Server (such as nginx or Cherokee) and Java/GlassFish - ALL on a single-machine running FreeBSD with 32 GB of RAM, how will they perform? Note that by going with this approach, the entire 32

django and riak engine not found

由 女生的网名这么多〃 提交于 2020-01-04 09:23:44
问题 i have this error with django riak engine : django.core.exceptions.ImproperlyConfigured: 'django_riak_engine.riak' isn't an available database backend. Try using django.db.backends.XXX, where XXX is one of: I've installed all the dependencies needed. Here is my settings.py : # Django settings for Lin project. DEBUG = True TEMPLATE_DEBUG = DEBUG ADMINS = ( # ('Your Name', 'your_email@example.com'), ) MANAGERS = ADMINS DATABASES = { 'default': { 'ENGINE': 'django_riak_engine.riak', 'NAME':

Completely confused about MapReduce in Riak + Erlang's riakc client

由 我只是一个虾纸丫 提交于 2020-01-01 22:14:54
问题 The main thing I'm confused about here (I think) is what the arguments to the qfun are supposed to be and what the return value should be. The README basically doesn't say anything about this and the example it gives throws away the second and third args. Right now I'm only trying to understand the arguments and not using Riak for anything practical. Eventually I'll be trying to rebuild our (slow, MySQL-based) financial reporting system with it. So ignoring the pointlessness of my goal here,

Explain Merkle Trees for use in Eventual Consistency

由 别说谁变了你拦得住时间么 提交于 2019-12-31 07:53:05
问题 Merkle Trees are used as an anti-entropy mechanism in several distributed, replicated key/value stores: Dynamo Riak Cassandra No doubt an anti-entropy mechanism is A Good Thing - transient failures just happen, in production. I'm just not sure I understand why Merkle Trees are the popular approach. Sending a complete Merkle tree to a peer involves sending the local key-space to that peer, along with hashes of each key value, stored in the lowest levels of the tree. Diffing a Merkle tree sent

Getting MapReduce results on RIAK (using the Java client)

由 女生的网名这么多〃 提交于 2019-12-31 05:01:27
问题 I am storing Person POJOs (4 string fields - id, name, lastUpdate, Data) on RIAK, then trying to fetch these objects with MapReduce. I am doing it very similar to Basho documentation: BucketMapReduce m = riakClient.mapReduce("person"); m.addMapPhase(new NamedJSFunction("Riak.mapByFields"), true); MapReduceResult result = m.execute(); Collection<Person> tmp = result.getResult(Person.class); the Person's String constructor is invoked: public Person(String str){} (I must have this constructor,

Links in Riak: what can they do/not do, compared to graph databases?

由 ℡╲_俬逩灬. 提交于 2019-12-30 04:56:25
问题 The familiar Neo4j treats relationships as first class citizens; ad hoc queries/ traversals, integrity (if one node is deleted, the link is gone) etc. It also advertises as the only mechanism to denote relations as well as outperform joins of relational DBs. How powerful are Riak links to denote relationships? Can they be used to answer ad-hoc queries like "fetch a list of hobbies for each such person who earns more than x" or friend of a friend, assuming suitable features like secondary
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