Tag Archives: MEP

Зукърбърг е приел поканата на Европейския парламент, но няма да има публично изслушване

Post Syndicated from nellyo original https://nellyo.wordpress.com/2018/05/17/fb_ep_transp/

Вера Йоурова, член на ЕК – Антонио Таяни, председател на ЕП – и брюкселска журналистка обменят мисли в Туитър.  Зукърбърг пристига в Брюксел “вероятно следващата седмица” – но няма да има публично изслушване, казва Йоурова.  – Не е ваша работа, казва Таяни.  – Гласувани сте от нас, наша работа е, пише Дженифър Бейкър (@BrusselsGeek) – Говоря на Йоурова, пояснява Таяни.








How to migrate a Hue database from an existing Amazon EMR cluster

Post Syndicated from Anvesh Ragi original https://aws.amazon.com/blogs/big-data/how-to-migrate-a-hue-database-from-an-existing-amazon-emr-cluster/

Hadoop User Experience (Hue) is an open-source, web-based, graphical user interface for use with Amazon EMR and Apache Hadoop. The Hue database stores things like users, groups, authorization permissions, Apache Hive queries, Apache Oozie workflows, and so on.

There might come a time when you want to migrate your Hue database to a new EMR cluster. For example, you might want to upgrade from an older version of the Amazon EMR AMI (Amazon Machine Image), but your Hue application and its database have had a lot of customization.You can avoid re-creating these user entities and retain query/workflow histories in Hue by migrating the existing Hue database, or remote database in Amazon RDS, to a new cluster.

By default, Hue user information and query histories are stored in a local MySQL database on the EMR cluster’s master node. However, you can create one or more Hue-enabled clusters using a configuration stored in Amazon S3 and a remote MySQL database in Amazon RDS. This allows you to preserve user information and query history that Hue creates without keeping your Amazon EMR cluster running.

This post describes the step-by-step process for migrating the Hue database from an existing EMR cluster.

Note: Amazon EMR supports different Hue versions across different AMI releases. Keep in mind the compatibility of Hue versions between the old and new clusters in this migration activity. Currently, Hue 3.x.x versions are not compatible with Hue 4.x.x versions, and therefore a migration between these two Hue versions might create issues. In addition, Hue 3.10.0 is not backward compatible with its previous 3.x.x versions.

Before you begin

First, let’s create a new testUser in Hue on an existing EMR cluster, as shown following:

You will use these credentials later to log in to Hue on the new EMR cluster and validate whether you have successfully migrated the Hue database.

Let’s get started!

Migration how-to

Follow these steps to migrate your database to a new EMR cluster and then validate the migration process.

1.) Make a backup of the existing Hue database.

Use SSH to connect to the master node of the old cluster, as shown following (if you are using Linux/Unix/macOS), and dump the Hue database to a JSON file.

$ ssh -i ~/key.pem [email protected]
$ /usr/lib/hue/build/env/bin/hue dumpdata > ./hue-mysql.json

Edit the hue-mysql.json output file by removing all JSON objects that have useradmin.userprofile in the model field, and save the file. For example, remove the objects as shown following:

  "pk": 1,
  "model": "useradmin.userprofile",
  "fields": {
    "last_activity": "2018-01-10T11:41:04",
    "creation_method": "HUE",
    "first_login": false,
    "user": 1,
    "home_directory": "/user/hue_admin"

2.) Store the hue-mysql.json file on persistent storage like Amazon S3.

You can copy the file from the old EMR cluster to Amazon S3 using the AWS CLI or Secure Copy (SCP) client. For example, the following uses the AWS CLI:

$ aws s3 cp ./hue-mysql.json s3://YourBucketName/folder/

3.) Recover/reload the backed-up Hue database into the new EMR cluster.

a.) Use SSH to connect to the master node of the new EMR cluster, and stop the Hue service that is already running.

$ ssh -i ~/key.pem [email protected]
$ sudo stop hue
hue stop/waiting

b.) Connect to the Hue database—either the local MySQL database or the remote database in Amazon RDS for your cluster as shown following, using the mysql client.

$ mysql -h HOST –u USER –pPASSWORD

For a local MySQL database, you can find the hostname, user name, and password for connecting to the database in the /etc/hue/conf/hue.ini file on the master node.

    engine = mysql
    name = huedb
    case_insensitive_collation = utf8_unicode_ci
    test_charset = utf8
    test_collation = utf8_bin
    host = ip-172-31-37-133.us-west-2.compute.internal
    user = hue
    test_name = test_huedb
    password = QdWbL3Ai6GcBqk26
    port = 3306

Based on the preceding example configuration, the sample command is as follows. (Replace the host, user, and password details based on your EMR cluster settings.)

$ mysql -h ip-172-31-37-133.us-west-2.compute.internal -u hue -pQdWbL3Ai6GcBqk26

c.) Drop the existing Hue database with the name huedb from the MySQL server.


d.) Create a new empty database with the same name huedb.


e.) Now, synchronize Hue with its database huedb.

$ sudo /usr/lib/hue/build/env/bin/hue syncdb – noinput
$ sudo /usr/lib/hue/build/env/bin/hue migrate

(This populates the new huedb with all Hue tables that are required.)

f.) Log in to MySQL again, and drop the foreign key to clean tables.

mysql> SHOW CREATE TABLE huedb.auth_permission;

In the following example, replace <id value> with the actual value from the preceding output.

mysql> ALTER TABLE huedb.auth_permission DROP FOREIGN KEY
content_type_id_refs_id_<id value>;

g.) Delete the contents of the django_content_type

mysql> DELETE FROM huedb.django_content_type;

h.) Download the backed-up Hue database dump from Amazon S3 to the new EMR cluster, and load it into Hue.

$ aws s3 cp s3://YourBucketName/folder/hue-mysql.json ./
$ sudo /usr/lib/hue/build/env/bin/hue loaddata ./hue-mysql.json

i.) In MySQL, add the foreign key content_type_id back to the auth_permission

mysql> use huedb;
mysql> ALTER TABLE huedb.auth_permission ADD FOREIGN KEY (`content_type_id`) REFERENCES `django_content_type` (`id`);

j.) Start the Hue service again.

$ sudo start hue
hue start/running, process XXXX

That’s it! Now, verify whether you can successfully access the Hue UI, and sign in using your existing testUser credentials.

After a successful sign in to Hue on the new EMR cluster, you should see a similar Hue homepage as shown following with testUser as the user signed in:


You have now learned how to migrate an existing Hue database to a new Amazon EMR cluster and validate the migration process. If you have any similar Amazon EMR administration topics that you want to see covered in a future post, please let us know in the comments below.

Additional Reading

If you found this post useful, be sure to check out Anomaly Detection Using PySpark, Hive, and Hue on Amazon EMR and Dynamically Create Friendly URLs for Your Amazon EMR Web Interfaces.

About the Author

Anvesh Ragi is a Big Data Support Engineer with Amazon Web Services. He works closely with AWS customers to provide them architectural and engineering assistance for their data processing workflows. In his free time, he enjoys traveling and going for hikes.

Astro Pi Mission Zero: your code is in space

Post Syndicated from David Honess original https://www.raspberrypi.org/blog/astro-pi-mission-zero-day/

Every school year, we run the European Astro Pi challenge to find the next generation of space scientists who will program two space-hardened Raspberry Pi units, called Astro Pis, living aboard the International Space Station.

Italian ESA Astronaut Paolo Nespoli with the Astro Pi units. Image credit ESA.

Astro Pi Mission Zero

The 2017–2018 challenge included the brand-new non-competitive Mission Zero, which guaranteed that participants could have their code run on the ISS for 30 seconds, provided they followed the rules. They would also get a certificate showing the exact time period during which their code ran in space.

Astro Pi Mission Zero logo

We asked participants to write a simple Python program to display a personalised message and the air temperature on the Astro Pi screen. No special hardware was needed, since all the code could be written in a web browser using the Sense HAT emulator developed in partnership with Trinket.

Scott McKenzie on Twitter

Students coding #astropi emulator to scroll a message to astronauts on @Raspberry_Pi in space this summer. Try it here: https://t.co/0KURq11X0L #Rm9Parents #CSforAll #ontariocodes

And now it’s time…

We received over 2500 entries for Mission Zero, and we’re excited to announce that tomorrow all entries with flight status will be run on the ISS…in SPAAACE!

There are 1771 Python programs with flight status, which will run back-to-back on Astro Pi VIS (Ed). The whole process will take about 14 hours. This means that everyone will get a timestamp showing 1 February, so we’re going to call this day Mission Zero Day!

Part of each team’s certificate will be a map, like the one below, showing the exact location of the ISS while the team’s code was running.

The grey line is the ISS orbital path, the red marker shows the ISS’s location when their code was running. Produced using Google Static Maps API.

The programs will be run in the same sequence in which we received them. For operational reasons, we can’t guarantee that they will run while the ISS flies over any particular location. However, if you have submitted an entry to Mission Zero, there is a chance that your code will run while the ISS is right overhead!

Go out and spot the station

Spotting the ISS is a great activity to do by yourself or with your students. The station looks like a very fast-moving star that crosses the sky in just a few minutes. If you know when and where to look, and it’s not cloudy, you literally can’t miss it.

Source Andreas Möller, Wikimedia Commons.

The ISS passes over most ground locations about twice a day. For it to be clearly visible though, you need darkness on the ground with sunlight on the ISS due to its altitude. There are a number of websites which can tell you when these visible passes occur, such as NASA’s Spot the Station. Each of the sites requires you to give your location so it can work out when visible passes will occur near you.

Visible ISS pass star chart from Heavens Above, on which familiar constellations such as the Plough (see label Ursa Major) can be seen.

A personal favourite of mine is Heavens Above. It’s slightly more fiddly to use than other sites, but it produces brilliant star charts that show you precisely where to look in the sky. This is how it works:

  1. Go to www.heavens-above.com
  2. To set your location, click on Unspecified in the top right-hand corner
  3. Enter your location (e.g. Cambridge, United Kingdom) into the text box and click Search
  4. The map should change to the correct location — scroll down and click Update
  5. You’ll be taken back to the homepage, but with your location showing at the top right
  6. Click on ISS in the Satellites section
  7. A table of dates will now show, which are the upcoming visible passes for your location
  8. Click on a row to view the star chart for that pass — the line is the path of the ISS, and the arrow shows direction of travel
  9. Be outside in cloudless weather at the start time, look towards the direction where the line begins, and hope the skies stay clear

If you go out and do this, then tweet some pictures to @raspberry_pi, @astro_pi, and @esa. Good luck!

More Astro Pi

Mission Zero certificates will be arriving in participants’ inboxes shortly. We would like to thank everyone who participated in Mission Zero this school year, and we hope that next time you’ll take it one step further and try Mission Space Lab.

Mission Zero and Mission Space Lab are two really exciting programmes that young people of all ages can take part in. If you would like to be notified when the next round of Astro Pi opens for registrations, sign up to our mailing list here.

The post Astro Pi Mission Zero: your code is in space appeared first on Raspberry Pi.