March 12, 2014
Druid is an open source analytics platform designed for real-time, exploratory queries on large-scale data sets. Druid is useful for use cases requiring interactive and fast exploration of large amounts of data (10s of billions of events added per day, 10s of TB of data added per day) and always-on availability.
The output of Druid’s indexing process is stored in deep storage. Deep storage provides a durable store for segments that feed the Druid query nodes. As long as Druid nodes can see this storage infrastructure and access the segments stored on it, there will be no data loss no matter how many Druid nodes are lost. For deep storage, Druid supports local mounts, HDFS, and S3 or S3-compatible APIs (like Riak CS). S3-compatible API is the default for deep storage.
For a cost-effective, highly available alternative to S3, Riak CS fits nicely with Druid. Druid has released a guide to walk users through how to use Riak CS as deep storage in Druid. The full guide is available here: https://github.com/metamx/druid/wiki/Stand-Alone-With-Riak-CS
February 19, 2014
Basho is excited to announce that Yahoo! JAPAN has launched its new cloud storage service platform for the enterprise market in Japan, powered by Riak CS. Yahoo! JAPAN is the one of the most comprehensive web portals and the most popular search engine in Japan, surpassing Google.
Riak CS is Basho’s cloud storage software that combines Amazon-class economics with the ability to customize and extend. It is built on Riak, Basho’s distributed database that is highly efficient at storing and retrieving objects, even under extreme usage or failure scenarios. For extensibility, Riak CS adds compatibility with the Amazon S3 and OpenStack Swift API.
Yahoo! JAPAN is pushing hard to be number one in transaction value across the Japanese e-commerce marketplace. LOHACO, a popular internet shopping site operated by ASKUL Corporation, has been using Basho’s Riak CS solution via Yahoo! JAPAN as backend storage for almost a year. Riak CS has proven to be a very stable system for LOHACO’s needs.
“Enterprises require storage services that are cost-effective, reliable, and scalable. Yahoo! JAPAN has been able to create a cloud storage solution to meet these needs, as well as deliver access to our large networks and server infrastructure, by developing on Riak and Riak CS,” said Shingo Saito, Cloud Product Manager at Yahoo! JAPAN. “Our partnership with Basho allows us to continue to build features that are beneficial to major enterprises and constantly improve our Cloud Storage Service by integrating with Riak, Riak CS, and future products from Basho.”
Basho is proud of Yahoo! JAPAN’s cloud service. We are excited to be a part of this great milestone.
October 2, 2013
What Is Riak CS?
In May of this year, we posted the top 5 questions we heard from customers and our community about Riak CS; today we’ll take a deeper dive into the technical details, specifically the differences between Riak CS and Riak itself.
Riak CS as Compared to Riak
Both Riak CS and Riak are, at their core, places to store objects. Both are open source and both are designed to be used in a cluster of servers for availability and scalability.
The fundamental distinction between the two is simple: Riak CS can be used for storing very large objects, into the terabyte size range, while Riak is optimized for fast storage and retrieval of small objects (typically no more than a few megabytes).
There are subtle differences; however, that can be obscured by the similarities between the two.
Why Would I Use Riak CS?
Riak CS is used for a variety of reasons. Some examples:
- Private object storage services, for example for companies that want to store sensitive data behind their own firewalls.
- Large binary object storage as part of a voice or video service.
- An integrated component in an OpenStack cloud solution, storing and serving VM images on demand.
Tier 3, Yahoo! Japan, Datapipe, and Turner Broadcasting are just a few of the big names using Riak CS today.
What Does Riak CS Do That Riak Doesn’t?
Riak CS carves large objects into small chunks of data to be distributed throughout a Riak cluster and, when used with Riak CS Enterprise, synchronized with remote data centers.
Riak CS adds compatibility with Amazon’s S3 and OpenStack’s Swift APIs. These offer very different semantics than Riak, and the advanced search capabilities in Riak such as Secondary Indexes and full text search are not available using S3 or Swift clients.
We strongly advise against it, but it is possible to work with Riak’s standard APIs “under the hood” when deploying a Riak CS solution.
Work is actively underway to add a security model to Riak in the upcoming 2.0 release.
Buckets or Buckets?
Users of Riak CS store their objects in virtual containers (called buckets in Amazon S3 parlance, containers in OpenStack).
Riak also relies heavily on buckets for data storage and configuration but, despite the names, these buckets are not the same.
As an example of how this can cause confusion: the replication factor in Riak (the number of times a piece of data is stored in a cluster) is configurable per-bucket. Because Riak’s buckets do not underly the user buckets in Riak CS, this feature cannot be used to create tiered services.
Riak is designed to maximize availability; the price paid for that is delayed consistency when the network is split and clients are writing to both sides of the cluster.
Creating user accounts in Riak CS; however, led to the need for a mechanism to maintain strong consistency. If two people attempt to create user accounts with the same username on either side of a network partition, both cannot be allowed to succeed, or else a conflict will occur that is very difficult to automatically recover from.
Furthermore, user buckets in S3 (and OpenStack APIs as implemented in Riak CS) reside in a global rather than a user-specific namespace, so bucket creation must also be handled carefully.
Riak CS introduced a service named Stanchion that is designed to handle these specific requests to avoid conflicts. Stanchion is a single process running on a single Riak server (thus introducing a single point of failure for user account and bucket creation requests).
While it is possible to deploy Stanchion using common system tools to make a daemon process run in a highly available manner, Basho recommends doing so carefully and testing it thoroughly. Since the only impact of failure is to prevent user and bucket creation, it may be preferable to monitor and alert on failure. If two copies of Stanchion are running due to a network partition, its strong consistency guarantees will be lost.
With strong consistency options targeted for Riak 2.0, expect to see some changes.
Basho offers multi-datacenter replication with its Enterprise software licenses, and Riak CS Enterprise takes full advantage of that feature. Data can be written to one or more clusters in multiple data centers and be synchronized automatically between them.
There are two types of synchronization: real-time, which occurs as objects are written, and full sync, which happens on a periodic basis to compare the full contents of each cluster for any changes to be merged.
One key difference is that Riak CS maintains manifest files to track the chunks it creates, and it is these manifests that are distributed between clusters during real-time sync. The individual chunks are not synchronized until a full sync replication occurs, or until someone requests the file from a remote cluster. The manifest is made active for someone to retrieve the chunks after the original upload to the source cluster is complete.
A common mistake while installing Riak CS is to configure it using information specific to Riak rather than Riak CS. As an example, per the Riak CS installation instructions the relevant backend data store must be configured to
riak_cs_kv_multi_backend, which is forked from Riak’s
riak_kv_multi_backend. Using the latter will cause problems.
Riak (CS) Control
Exposure to Internet
Exposing any database directly to the Internet is risky. Riak, currently lacking any concept of authentication, absolutely must not be accessible to untrusted networks.
Riak CS; however, is designed with Internet access in mind. It is still advisable to place a load balancer or proxy in front of a Riak CS cluster, for example to ease cluster maintenance/upgrades and to provide a central location to log and block potentially hostile access.
Riak CS servers will still have open Riak ports that must be protected from the Internet as you would any Riak servers.
Where to Next for Riak CS?
2013 has been a big year for Riak CS: it was released as open source in the spring, with OpenStack support added this summer. Still, there is much to do.
As mentioned above, improving or replacing Stanchion is a high priority.
We will continue to expand the API coverage for Riak CS. The next major targets are the copy object operations that Amazon S3 and OpenStack Swift offer.
Compression and more granular replication controls are also under consideration for future releases.
By building Riak CS atop the most robust open source distributed database in the world, we’ve created a very operationally friendly, powerful storage solution that can evolve to meet present and future needs. Feel free to give it a try if you aren’t already using it.
If you’re interested in hearing from the engineers who’ve made this software possible (and seeing just how far a highly available data storage solution can take you), join us October 29-30th for RICON West. RICON West is where Basho brings together industry and academia to discuss the rapidly expanding world of distributed systems, including Riak and Riak CS.
September 26, 2013
Big Data. eCommerce. Mobile. Suddenly, information technology has shifted from cost center to business opportunity. This opportunity favors fast movers with the ability to rapidly execute on emerging trends. Therefore, the length of traditional IT procurement cycles and provisioning processing has become a significant barrier to capitalizing on these opportunities. To increase their operational agility, some organizations are employing public infrastructure as a service (IaaS) or cloud providers (such as Amazon Web Services and Joyent) to rapidly provision compute and storage resources. However, technical incompatibilities, regulatory restrictions, cost at scale, and/or existing capital investments prevent many organizations from utilizing public cloud providers to achieve this operational agility. Private clouds allow these organizations to realize the value of public clouds with the flexibility to comply with their unique combination business and technical requirements.
Fundamentally, a cloud (public or private) creates a composable infrastructure with the following capabilities:
- Resource Pooling: Presents compute, storage, and network resources through a unified set of vendor neutral abstractions and manages them based on service-level requirements.
- Rapid Elasticity: Optimizes resource allocation based on performance relative to service-level requirements.
- Self Service: Delegates management responsibilities for a subset of the infrastructure resources to end-users.
- Metering/Charge Back: Records resource utilization on a per customer basis to support usage billing.
Private clouds implement these characteristics by orchestrating infrastructure provisioning and management through the following services:
- Compute: Physical or virtual machines with a specified number of processing cores and RAM.
- Block Storage: Random access, read/write persistent storage capable of supporting disk partitioning and file systems.
- Object Storage: Write-once, read-many (WORM) oriented storage for large files (multiple gigabytes to terabytes in size) accessed through a key-value oriented interface.
- Network: Network topology definition and connectivity management between compute, block storage, and object storage services, as well as public networks such as the Internet.
Typically, these services are exposed via an HTTP API, as well as a web-based dashboard allowing end-users to simultaneously script complex workflows and visualize their infrastructure.
Superficially, private clouds appear to be traditional virtualization infrastructures with a web interface and HTTP API. While both models share a number of common components, cloud infrastructures achieve reliability by horizontally scaling commodity hardware instead of vertically scaling specialized hardware. The following table contrasts the storage strategies employed by the traditional virtualization and cloud models:
|Data Type||Traditional Virtualization||Cloud|
|Application Data||VM direct attached storage (e.g. NAS, SAN, etc)||Elastic database service (e.g. Riak)|
|Static Content||VM direct attached storage||Object Storage (e.g. Riak CS)|
|Templates||VM direct attached storage||Object Storage (e.g. Riak CS)|
|Backups||VM direct attached storage||Object Storage (e.g. Riak CS)|
Static content, templates, and backups typically represent the majority of a system’s storage consumption. Employing object storage to manage this data brings the following benefits to private cloud infrastructures:
- Reduced Hardware Costs: By replicating multiple copies of data across a cluster of services, object storage systems such as Riak CS guarantee data durability through software rather than hardware. This approach allows users to employ cheaper commodity hardware using ubiquitous SATA/SAS storage subsystems without sacrificing reliability.
- Horizontal Scalability: Since storage coordination and data replication occurs in software, storage is expanded by simply adding new servers to the cluster.
- Operational Simplicity: Accessed via HTTP/HTTPS, object storage systems provide secure access to data using a simple, ubiquitous protocol. Unlike iSCSI and Fiber Channel solutions, this approach typically has little to no impact on network infrastructure designs.
The Apache CloudStack IaaS platform has supported Swift-based object storage since version 4.0.0 and S3-based object storage since version 4.1.0. With the 4.2.0, CloudStack supports S3 and Swift as native secondary storage devices – allowing the system to provision and backup VMs directly from an object store. When coupled with Riak CS Enterprise, Apache CloudStack-based clouds are able to replicate template and snapshot data across multi-data centers to meet off-site backup and disaster recovery requirements.
The OpenStack Object Storage API specifies the semantics of OpenStack’s object storage service. The Swift implementation of this API is provided as the default implementation of this API. With the 1.4.0 release, Riak CS implements both the OpenStack Object Storage API allowing it to serve as a drop-in Swift replacement.
As organizations work to understand the opportunities created by information technology, private clouds have emerged as a key component of their strategies to increase operational agility. While private clouds can be constructed using traditional virtualization approaches, such designs will simply mask core infrastructure brittleness and high infrastructure costs. By embracing design principles such as object storage that underpin cloud infrastructure platforms, organizations can realize the promise of increased operational agility and cost savings.
April 17, 2013
Riak CS Control is a standalone user management interface for Riak CS, Basho’s cloud storage software. Riak CS Control provides a user interface for filtering, disabling, creating, and managing users.
To help get you started with Riak CS Control, we have put together a short video that walks you through the installation and configuration. It also goes over the basics of how to create and manage users.