What is HDF5 server?
HDF Server is a freely available service (implemented in Python using the Tornado framework) that enables remote access to HDF5 content using a RESTful API (more about that in a bit).
How do I get HDF4 to work with HDF5?
For HDF4 access to work, the library must be built with netCDF-4 features. Here's an example, assuming the HDF5 library has been built and installed in H5DIR and you will build and install the HDF4 library in H4DIR (which could be the same as H5DIR).
How does F5 handle secure remote access?
How Does F5 Handle Secure Remote Access? F5 has a host of access security solutions purpose-built to keep good traffic flowing and bad traffic out. BIG-IP Access Policy Manager (APM) lets you create identity-aware, context-based access policies, implement an SSO solution, and create an SSL VPN.
Can I run HDF server on my own system?
If you would like to try out running HDF Server on your own system, code is available on Github (see link below). Please let us know what you think – leave us a comment!
Can Excel open HDF5?
To access the data in HDF5 files from Excel is a frontrunner among the all-time TOP 10 most frequently asked for features. A spreadsheet tool might be a convenient window into, and user interface for, certain data stored in HDF5 files.
Is HDF5 secure?
HDF5 files only contain data -- no scripts or code. Should be safe. @kcw78 How is different from pickle files? Pickle files also store data but can introduce malicious scripts while loading.
When should I use HDF5?
Supports Large, Complex Data: HDF5 is a compressed format that is designed to support large, heterogeneous, and complex datasets. Supports Data Slicing: "Data slicing", or extracting portions of the dataset as needed for analysis, means large files don't need to be completely read into the computers memory or RAM.
How do I view HDF5 files in Windows?
Open a HDF5/H5 file in HDFView hdf5 file on your computer. Open this file in HDFView. If you click on the name of the HDF5 file in the left hand window of HDFView, you can view metadata for the file. This will be located in the bottom window of the application.
Is HDF5 faster than CSV?
(a) Categorical Features as Strings An interesting observation here is that hdf shows even slower loading speed that the csv one while other binary formats perform noticeably better.
Is HDF5 better than CSV?
HDF5 stores data in binary format native to a computing platform but portable across platforms. The binary format native to computers makes the format the more efficient for computers than text formats (e.g., . txt or . csv) that is meant for humans to read.
What is the advantage of HDF5?
HDF5 Advantages: Organization, flexibility, interoperability Some of the main advantages of HDF5 are its hierarchical structure (similar to folders/files), optional arbitrary metadata stored with each item, and its flexibility (e.g. compression).
How do I read a HDF5 file?
Reading HDF5 files To open and read data we use the same File method in read mode, r. To see what data is in this file, we can call the keys() method on the file object. We can then grab each dataset we created above using the get method, specifying the name. This returns a HDF5 dataset object.
How do I open HDF files online?
If you cannot open your HDF file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a HDF file directly in the browser: Just drag the file onto this browser window and drop it.
What is HDF5 viewer?
HDFView is a visual tool, written in Java, suitable for browsing and editing HDF (Hierarchical Data Format) (HDF5 and HDF4) files, such as the SMOS L2 data. Using HDFView, you can: View a file hierarchy in a tree structure. Create new files, add or delete groups and datasets. View and modify the content of a dataset.
How popular is HDF5?
HDF5 is one of the most popular and reliable formats for non-tabular, numerical data. Let me give you an example. NASA's Earth Observing System satellites gather around 16 TBs of data a day in the HDF5 format.
Is HDF5 lossless?
HDF5 also supports lossless compression of datasets.
Is HDF5 the same as H5?
Just different file extensions, but otherwise the files will be identical. *. h5 and *. hdf5 are synonymous file extensions.
Is HDF5 Hadoop?
The Hadoop Distributed File System (HDFS) HDF5 Connector is a virtual file driver (VFD) that allows you to use HDF5 command line tools to extract metadata and raw data from HDF5 and netCDF4 files on HDFS, and use Hadoop streaming to collect data from multiple HDF5 files.
When reading data from remote locations, must you specify filename as the full path to an HDF5 file using?
When reading data from remote locations, you must specify filename as the full path to an HDF5 file using a uniform resource locator (URL). For example, to read a dataset in an HDF5 file from Amazon S3™, specify the full URL for the file:
What is H5F.mount?
H5F.mount (locID,name,childID,plistID) mounts the file specified by childID onto the group specified by locID and name using the mount properties specified by pli stID.
What is newfileID in HDF5?
newfileID = H5F.reopen (fileID) returns a new file identifier for the open HDF5 file specified by fileID.
What does H5F.close do?
H5F.close (fileID) terminates access to the HDF5 file identified by fileID and flushes all data to storage.
What is faplID in a file?
faplID — File access property list identifier, specified as 'H5P_DEFAULT', in which case the default I/O settings are used.
What is hitrate in mdc?
hitRate = H5F.get_mdc_hit_rate (fileID) queries the metadata cache of the target file to obtain its hit-rate since the last time hit-rate statistics were reset. If the cache has not been accessed since the last time the hit-rate statistics were reset, the hit-rate is defined to be 0.0.
Does H5F.open read or write?
H5F.open does not support reading or writing to files stored remotely in HDFS™ when you specify the file access flag as 'H5F_ACC_RDWR'. Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.
How Does F5 Handle Secure Remote Access?
F5 has a host of access security solutions purpose-built to keep good traffic flowing and bad traffic out. BIG-IP Access Policy Manager (APM) lets you create identity-aware, context-based access policies, implement an SSO solution, and create an SSL VPN.
Why is remote access important?
Why is Secure Remote Access Important? With the proliferation of internet-connected devices, an organization’s workforce is no longer sequestered to a single location. Instead, an organization may have employees connecting to their internal network and accessing sensitive data from locations across the globe.
What is desktop sharing?
Desktop sharing – Provides a user with real-time access to files and data located on another device
Converting HDF5 to MDSplus
The HDF5 to MDSplus converter is called hdf5ToMds. It takes the following form:
Accessing HDF5 files from MDSplus applications
The HDF5 accessor functions allow MDSplus aware applications to access HDF5 files directly. There are four functions:
Building the HDF5 tools
The hdf5 tools are provided as part of the standard MDSplus distribution. They are built by the top level makefile if the libraries and includes can be found at 'configure' time. By default the MDSplus configure script decides to build the HDF5 tools if the file hdf5.h can be found in the system include directories.
Why A Restful API?
- Various means of accessing HDF5 content over the net have been around about as long as HDF itself (or the Internet for that matter). Why a new API? Could we not just extend the existing HDF5 API via some form of RPC (remote procedure call)? Not really – in short, what works well in the c…
What Is Rest?
- REST is an architectural pattern, typically HTTP-based, that has the following properties: 1. Stateless – the server does not maintain any client state (this enables better scalability). 2. Resources are identified in the request. For example, an operation on an attribute should identify that attribute via a URI (Uniform Resource Identifier). 3. Uses all the HTTP methods: GET, PUT, D…
A Few Examples
- Let’s consider some typical requests you can make to HDF Server to illustrate how the API works. We’ve set up an instance of HDF Server on Amazon AWS, so you can try out the server without downloading and running it yourself. If you enter the following URL in your browser address bar: https://data.hdfgroup.org:7258/?host=tall.data.hdfgroup.org, the server will receive a GET reque…
Data Selection
- When it comes to fetching the values, there might be some cause for concern. Suppose the dataset dimensions are 1024 x 1024 x 1024 x 1024. You could be waiting quite some time for the response containing 1 TB of data to get to you! Luckily, there are a few ways to be somewhat more selective about the specific data values to be sent by the server. The query option “select” …
Updating Data
- So far, we’ve had a brief tour of different GET requests for fetching state information, but HDF Server supports the full spectrums of HTTP operations: 1. GET– retrieve a resource 2. PUT– create named resources (e.g. links), update data values 3. POST– create new domains, groups, datasets, committed datatypes 4. DELETE– remove a resource We won’t cover the specifics of u…
What’s Next
- The initial release of HDF Server is just a first step in extending HDF to the client/server world. Some ideas we’ve been looking at include: 1. HDF5 client library – This would be an HDF5 API-compatible library that would map HDF5 calls to the equivalent REST API’s. This would enable existing HDF5 applications to utilize read/write to the server without any changes needed to the …
Links
- Download: github.com/HDFGroup/h5serv
- Documentation: h5serv.readthedocs.org/en/latest/index.html
- RESTful HDF5 paper: support.hdfgroup.org/pubs/papers/RESTful_HDF5.pdf
- REST architecture: en.wikipedia.org/wiki/Representational_state_transfer
Providing A Secure System on A Network
Authentication
- There have been various HTTP protocols developed over the years (e.g. OAuth and OpenID) to provide authentication services. One of the oldest and simplest protocols is basic access authentication. HDF Server now supports basic authentication out of the box, and it is easy to plug in alternative authentication frameworks as desired. [ Note: transmitted credentials in basic acc…
Encryption
- We’ve all seen some form of a padlock icon next to the URL in our favorite browsers which indicates the security status of your session on any page that is exchanging secure information (e.g. banking app, email). A regular HTTP connection communicates “in the clear,” so anyone who can intercept between your browser and the server could potentially eavesdrop on the HTTP req…
Authorization
- Once the server has authenticated that the user is who he or she claims to be, the next step is to determine if the request should actually be granted. For example, just because “Joe” has a valid password, and has sent a request over HTTPS, it doesn’t necessarily mean that the server should honor any DELETErequests he may send. This is where authorization comes in. With normal HD…
Conclusion
- This has been a brief tour of some exciting new features for HDF Server. Our hope is that these features will enable the use of HDF Server (and HDF5) in ways that may not have been possible before. If you would like to try it out yourself, you can easily set up HDF Server on your own computer by following the instructions. Then create a password fi...