Category Archives: Hadoop

DELETED_BECAUSE_YOU_DIDNT_PASSWORD_PROTECT_YOUR_MONGODB

It’s been a very busy summer for yours truly and the rest of the database world.  Some interesting nouvelles (I thought so, at least) in case you missed them:

 

GET RID OF ORACLE!
The UK Government has ordered its agencies to “get rid of Oracle“. While Oracle have been shooting themselves in the foot spectacularly of late with their bedside manner, I have personal experience of the last time that the UKG wanted to replace them.

It didn’t go well. At all.

Nor did it go cheaply, which is all that anyone is caring about, of course.

Despite the horror stories in the media about how difficult it is to deal with Oracle’s support, sales and auditing teams, it’s still the best database out there by a country mile.

 

Ask … Someone Other Than Tom
It’s no longer possible to Ask Tom. Mr. Kyte has decided to take a very well-deserved sabbatical and has handed over Ask Tom duties to … someone who isn’t called Tom.

What a crazy world we live in.

I’m not going to lie – I definitely was dazzled by his stardom on more than one occasion. At a NEOUG conference in Cleveland, I managed to get him to sign a copy of his book and one of the most memorable moments of my DBA career was when I asked him a “great question” on a webinar many years ago. It helped me win an important argument at work, so I will always be thankful to him for that 🙂

 

Don’t Believe The Hype
Talking of which, not even Gartner thinks Big Data is worthy of the hype now. Instead of moving to their “Slope of Enlightenment” or “Plateau of Productivity”, it fell off their Hype Cycle for Emerging Technologies completely.

Oops.

 

NoSQL = NoPASSWORDS = NoDATA?
Maybe part of the reason is that the industry has realized that a lot of NoSQL databases just plain suck. Don’t forget that the “big” Hadoop story of 2015 is “Hadoop-on-SQL”, which would have been QUITE the juxtaposition eighteen months ago.

Still think NoSQL databases will replace relational databases? Then read this beauty and try and say that “relational databases are outdated” with a straight face.

While they found over a PETABYTE of unsecured data without too much trouble, probably the most noteworthy finding is that they found 347 different MongoDB databases called “DELETED_BECAUSE_YOU_DIDNT_PASSWORD_PROTECT_YOUR_MONGODB”.

 

 

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Leap Second 2015

L’Observatoire de Paris has decided that there will be a “leap second” on June 30th, 2015.  At 23:59:60 on this date, an additional second will be “inserted” into UTC (Coordinated Universal Time) to take into account the slightly irregular rotation of our planet.

The last “leap second” was on June 30th, 2012, when a bunch of servers running Linux had problems (including, and not limited to, Qantas Airways, reddit and anything running Hadoop).

This year, Google and Amazon both plan to implement a “leap smear” whereby they will add the “leap second” over an extended period on June 30th.

Be aware that a number of AWS services are affected and resolving issues with your EC2 instances is your responsibility.
 

The “Leap Second” and Oracle
The Oracle database requires no patches and has no problem with the “leap second” changes on the O/S level.

No action is required for Exadata servers which are NOT running 12.1.2.1.0.  If you ARE running this version, you will need to follow MOS note 1986986.1 to update your NTP configuration.
 

Linux Servers
However, any derivative of Red Hat Enterprise Linux (including Oracle Enterprise Linux, Oracle Unbreakable Enterprise Kernel and Asianux) versions 4.4 through 6.2, using kernel versions 2.4 to 2.6.39, may be affected.  This applies to both baremetal or virtualized environments.

In MOS 1472421.1, Oracle state that impacted servers may become unresponsive sometime before the “leap second” on June 30th, with the following seen in various logs (system, console, netconsole, etc):
 

INFO: task kjournald:1119 blocked for more than 120 seconds.
“echo 0 > /proc/sys/kernel/hung_task_timeout_secs” disables this message.
kjournald D ffff880028087f00 0 1119 2 0x00000000
ffff8807ac15dc40 0000000000000246 ffffffff8100e6a1 ffffffffb053069f
ffff8807ac22e140 ffff8807ada96080 ffff8807ac22e510 ffff880028073000
ffff8807ac15dcd0 ffff88002802ea60 ffff8807ac15dc20 ffff8807ac22e140

 
Alternatively, Java applications may suddenly start to use 100% of the CPU with the event “Leap second insertion causes futex to repeatedly timeout“.

The primary workaround is to stop the NTP service, reset the system clock and restart the NTP service:
 

/etc/init.d/ntpd stop
date -s “`date`”
/etc/init.d/ntpd start

 

An additional workaround is to reboot the server.
 

Oracle Enterprise Manager
Per MOS 1472651.1, any version of OEM from 10.2.0.5 to 12c running on Linux may see the OEM agent or the OMS service consume excessive CPU on or around “leap seconds”.

Suggested workarounds are identical to the Linux servers (reset the system clock or reboot the server).
 

Oracle Clusterware on Solaris Servers
Per MOS 759143.1, servers running Solaris 5.8 to 5.10 and running Oracle Clusterware 10.1 to 11.1 may suffer a node reboot unless they have the required patches.

The workaround for this issue is to configure the local xntpd daemon to disable PLL mode and enable skewing or apply Oracle Clusterware patch bundles / MLRs and increase the oprocd daemon timeout margin appropriately.
 

References

  • Leap seconds (extra second in a year) and impact on the Oracle database. (Doc ID 730795.1)
  • Leap Second Time Adjustment (e.g. on June 30, 2015 at 23:59:59 UTC) and Its Impact on Exadata Database Machine (Doc ID 1986986.1)
  • Enterprise Manager Management Agent or OMS CPU Use Is Excessive near Leap Second Additions on Linux (Doc ID 1472651.1)
  • NTP leap second event causing Oracle Clusterware node reboot (Doc ID 759143.1)
  • Leap Second Hang – CPU Can Be Seen at 100% (Doc ID 1472421.1)

 

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Random Links

In case you have a spare minute or two on your lunch break today …  Continue reading

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Big Data Blame

I thought I’d share a very interesting article on Big Data and its massively underwhelming (so far) business impact.

Might the trade mag hype machine be close to admitting that Big Data is a far more complicated beast than they have been suggesting? Surely not…

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Hadoop Rolls Out Transparent Encryption

This could be a big deal for Hadoop and enterprise adoption. End-to-end encryption should be a big winner, especially with support groups, as it’s largely been pushed to the sidebar until now.

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Oracle Big Data Lite VM 4.0

Following OpenWorld, Oracle released version 4.0 of their Big Data Appliance Lite Virtual Machine for VirtualBox.

It includes OEL 6.4, RDBMS database 12.1.0.2 with Big Data SQL, Cloudera 5.1.2, NoSQL database 3.0.14 and GoldenGate 12c.

The “Getting Started” page now has all sorts of good documentation, white papers and hands-on labs you can try out.

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Microsoft’s Analytics Platform System Appliance

In the last couple of months, Microsoft have repackaged their Parallel Data Warehouse appliance and now offer their new Analytics Platform System (APS) instead.

APS is a turnkey/black box appliance which offers the PDW, a Hadoop cluster (HDInsight, an implementation of Hortonworks) and an integration feature like Oracle’s Big Data SQL – called PolyBase – to allow the PDW to use the Hadoop data. Continue reading

2014 Gartner Hype Cycle

Gartner’s 2014 Hype Cycle was released earlier this month and shows, unsurprisingly, that Big Data and Cloud Computing are some way from reaching the prized “Plateau of Productivity” rating.

Continue reading

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Oracle Big Data SQL Primer

What is Big Data SQL?
Oracle Big Data SQL runs on the Big Data Appliance and allows an Oracle database to run one SQL query to pull data from disparate sources such as Hadoop, NoSQL and relational databases.

Continue reading

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