Cloud Computing:
The Hard Problems
Never Go Away
By Doug Tidwell, Cloud Computing Evangelist, IBM

Agenda
• A few (a very few) words about the cloud
• The hard problems (Boo!)
• Vendor lock-in and the Simple Cloud API
• Next steps / Resources
2

A few words about the cloud
3

Before the cloud
• If you wanted to start an
enterprise, you needed an IT
shop.
• Massive costs in hardware,
software, power,
administrative staff
• Prohibitive cost to entry
4

What if...
• You could have unlimited computing resources?
All the processing power you want
All the data storage you want
Data mining whenever you want
• Cloud computing will be the biggest change to our industry
since the rise of the Internet.
5

The cloud
•Cloud computing . . . is a style of computing where
IT-related capabilities are provided ‘as a service,’
allowing users to access technology-enabled
services ‘in the cloud’ without knowledge of,
expertise with or control over the technology
infrastructure that supports them.
From Wikipedia
•Everybody has a slightly different idea of what
cloud computing really is.
6

The cloud is here to stay
• Extremely stupid idea of assuming the entire planet just can
not be bothered with their own data (nor the security
thereof). As always there will be some who think they
'need' this. I hope this whole cloud [stuff] just goes away.
Logistically speaking it will never be anything but a waste of
money.
Posted by ___@gmail.com, who apparently just can not be
bothered with their own email (nor the security thereof).
7

Cloud characteristics
• Rapid elasticity
• Measured service
• On-demand self-service
• Ubiquitous network access
• Location-independent resource pooling
Source: NIST Working Definition of Cloud Computing,
http://csrc.nist.gov/groups/SNS/cloud-computing/
8

Cloud services
• There are four basic things people are doing in the cloud:
The application in the sky
The hard drive in the sky
The database in the sky
The machine in the sky
9

The hard problems never die
No matter how badly we want them to
10

The hard problems never die
• Whenever the industry embraces a technology, there’s
always the exhilaration of doing something new.
• Unfortunately, we still have to deal with the hard problems
like security, maintenance, lifecycle management, and so
forth.
We still have to build flexible applications that respond to changes
in the business environment.
We still have to share data and business processes with our
partners.
We’re not going back to building silos just because the cloud is
here.
• SOA isn’t going away just because the cloud is here.
11

Cloud computing requirements
• Management and governance
• Transactions and concurrency
• Identity
• Federated identity
• Security
• Location awareness
• Avoiding vendor lock-in
Common APIs for cloud storage, cloud databases, cloud middleware
• Common VM image format
12

Cloud computing requirements
• Data and application federation
• SLAs
• Lifecycle management
• Open client
• Metering and monitoring
• Deployment
13

Governance is hard
• Similarities between SOA and the cloud:
Both started bottom-up
Both started with massive hype
Both don’t work without governance
• You need an architect, a blueprint, and an executive who is both
enlightened and powerful.
• SOA and cloud computing aren’t simply coding issues.
14

Transactions and concurrency
• Many enterprise applications require transactions and
concurrency.
There needs to be only one copy of the data
Any changes to the data have to be synchronized
• This is very difficult to scale.
15

Cloud storage
• Most cloud storage systems, such as Amazon’s S3, are
designed as distributed, redundant systems.
Your data is stored on more than one disk in more than one place.
If one part of the system goes down, the rest of the system keeps going.
“There should never be a single point of failure” is a stated design goal.
• You can’t think of cloud storage as just another hard drive.
16

Cloud storage is not just a hard drive
• Once you create an object, it can’t be modified. You can
delete it or replace it, but you can’t modify it. (In S3, you
can’t even move it.)
• It takes time for changes to make their way throughout the
system (propagation latency).
If you just put an object into S3, you can’t be sure that it will be
available right away.
If you get an object from S3, you can’t be sure that it’s the latest
version.
17

Cloud storage is not just a hard drive
• Read and write requests will fail occasionally. Your
application should handle that gracefully.
Trying the request a second time usually does the trick.
Delete requests sometimes fail as well.
18

Cloud storage
• All of this is by design.
These design decisions mean that S3 is extremely scalable and
reliable.
But these design decisions also mean that S3 doesn’t work like
another hard drive.
• The right answer, as always, is to understand your choices,
understand your needs and pick the technology that works
best for you.
19

Cloud databases
• Cloud databases have similar design points.
Datasets are distributed for reliability
Some cloud databases support schemas, some don’t
Some cloud databases support joins, most don’t
Some cloud databases are relational, almost all aren’t
Some cloud databases are transactional, some aren’t
20

“Database” ≠ RDBMS
• Amazon’s SimpleDB is built around domains. Each domain
has some number of items; each item has some number of
attribute / value pairs.
No schema support
No queries across domains
• These design decisions make SimpleDB fast, scalable and,
well, simple.
But our previous discussions of propagation latency and I/O errors
apply here, too.
21

A wee quiz
• Is this a good idea?
count()
• How about this?
avg()
• Or one of these?
sum(), min(), max()
22

A wee quiz
• The answer: It depends.
SimpleDB automatically indexes your datasets, so the count()
operation is efficient. But everything is a string, so avg(), sum(),
min(), and max() aren’t supported.
Even if they are supported, they often aren’t efficient. If records
have to be retrieved from multiple servers in multiple data centers
just to calculate an average, that can take a long time.
23

Database design
• Many of us have learned over the years how to normalize an SQL
database.
But in the cloud, if the dataset is scattered across multiple machines in
multiple data centers and you can’t do joins across tables, you have to do
things differently.
• A denormalized database contains redundant data and often does
calculations at write time, not at read time.
A denormalized database is different from a poorly-designed database that
was never normalized to begin with.
24

Denormalizing your database
• The goal of a traditional, normalized relational database is to put
each piece of data into the system once and only once.
Building an application to use the data in a different way doesn’t require
changes to the database. (Hopefully.)
• With a denormalized database, the goal is to copy pieces of data
to minimize queries and processing power.
Building an application to use the data in a different way might require
changes to the database.
Updating data might require making the same change in multiple places.
25

Reliability
• If I have less physical control over my infrastructure, it’s
vital that the cloud be reliable as possible.
Some providers have SLAs that guarantee uptime and
responsiveness.
Some providers deliver private clouds via hosted or colocated data
centers.
• Reliability isn’t a new problem, but the cloud gives us
someone else to blame.
26

Security
• If I’m storing my data elsewhere, security as crucial as ever.
• If I’m running my applications elsewhere, security is as
crucial as ever.
Some cloud providers offer greater security, access to their
facilities, customized backup and recovery procedures, data
destruction, etc.
• Cloud computing doesn’t introduce any new security issues.
It doesn’t make them easier to solve, but it doesn’t create any new
ones.
• You can reuse much of your existing security infrastructure.
27

Identity
• Identity management, particularly federated identity
management, is crucial for cloud computing.
Technologies such as LDAP, OpenID, OAuth, etc. can be useful
here.
• You can reuse much of your existing authentication
infrastructure.
28

Regulatory issues
• Many enterprises can’t use a public cloud at all.
Laws prohibit certain types of data from being stored off-premises.
• The private cloud is an important architectural pattern
being used in many enterprises.
• Location awareness is a key concern for many (potential)
cloud users.
• Data retention and data destruction are important also.
29

Vendor lock-in
30

Vendor lock-in
• If there’s a new technology, any talented programmer will
want to use it.
Maybe the shiny new thing is appropriate for what we’re doing.
Maybe not.
We’re probably going to use it anyway.
• The challenge is to walk the line between using the newest,
coolest thing and avoiding vendor lock-in.
31

The Simple Cloud API
• A joint effort of Zend, GoGrid, IBM, Microsoft, Nirvanix and
Rackspace
But you can add your own libraries to support other cloud
providers.
• The goal: Make it possible to write portable, interoperable
code that works with multiple cloud vendors.
• simplecloud.org/
• An article on the Simple Cloud API was published on the
developerWorks Open Source zone today: bit.ly/1bSkTx
There’s also a Simple Cloud podcast at dW.
32

The Simple Cloud API
• Covers three areas:
File storage (S3, Nirvanix, Azure Blob Storage, Rackspace Cloud
Files)
Document storage (SimpleDB, Azure Table Storage)
Simple queues (SQS, Azure Table Storage)
• Uses the Factory and Adapter design patterns
A configuration file tells the Factory object which adapter to
create.
33

Vendor-specific APIs
• Listing all the items in a Nirvanix directory:
•$auth = array('username' => 'your-username',
'password' => 'your-password',
'appKey' => 'your-appkey');
$nirvanix = new Zend_Service_Nirvanix($auth);
$imfs = $nirvanix->getService('IMFS');
$args = array('folderPath' => '/dougtidwell',
'pageNumber' => 1,
'pageSize' => 5);
$stuff = $imfs->ListFolder($args);
34

Vendor-specific APIs
• Listing all the items in an S3 bucket:
•$s3 = new Zend_Service_Amazon_S3
($accessKey, $secretKey);
$stuff = $s3->getObjectsByBucket($bucketName);
35

The Simple Cloud API
• Listing all the items in a {Nirvanix directory | S3 bucket}:
•$credentials =
new Zend_Config_Ini($configFile);
$stuff = Zend_Cloud_Storage_Factory::getAdapter
($credentials)->listItems();
36

Where we go from here
It’s still early
37

Issues with the Internet
• “It’s not secure.”
• “I don’t want to lose control of my infrastructure.”
• “I don’t know how reliable it is.”
• “I don’t know if my partners are going to use it.”
• All of these were important, legitimate issues.
With VPNs and other technology, the industry solved these
problems.
38

Issues with the cloud
• “It’s not secure.”
• “I don’t want to lose control of my infrastructure.”
• “I don’t know how reliable it is.”
• “I don’t know if my partners are going to use it.”
• All of these are important, legitimate issues.
We’ve got some work to do, but the massive economic incentives
mean someone will find a way to solve these problems.
39

The hype, one more time
•Cloud computing will
be the biggest change
to our industry since
the rise of the
Internet.
40

Resources
Useful stuff
41

Other cloud sessions
• Cloud Computing with VMWare, Akhil Sahil
11:15 – 12:15 Wednesday
• PHP and the Cloud, Ivo Jansch
2:45 – 3:45 Wednesday
• PHP and Platform Independence in the Cloud, Wil Sinclair
9:15 – 10:15 Thursday
42

Cloud Computing with the Zend Framework
• A series of articles from the IBM developerWorks Open Source
zone:
Using Amazon S3 with Zend, September 22
• ibm.com/developerworks/opensource/library/os-php-cloud1/
Using Amazon EC2 with Zend, October 13
• ibm.com/developerworks/opensource/library/os-php-cloud2/
43

Principles of openness
1. Cloud providers must work together to ensure that the
challenges to cloud adoption are addressed through open
collaboration and the appropriate use of standards.
2. Cloud providers must not use their market position to
lock customers into their particular platforms and limiting
their choice of providers.
3. Cloud providers must use and adopt existing standards
wherever appropriate. The IT industry has invested
heavily in existing standards and standards organizations;
there is no need to duplicate or reinvent them.
44

Principles of openness
4. When new standards (or adjustments to existing
standards) are needed, we must be judicious and
pragmatic to avoid creating too many standards. We must
ensure that standards promote innovation and do not
inhibit it.
5. Any community effort around the open cloud should be
driven by customer needs, not merely the technical needs
of cloud providers, and should be tested or verified
against real customer requirements.
6. Cloud computing standards organizations, advocacy
groups, and communities should work together and stay
coordinated, making sure that efforts do not conflict or
overlap.
45

The principles in action
• The Cloud Computing Use
Cases Google group has a white
paper of common use cases.
• The identified use cases will be
used as input to various
standards efforts.
• Join us at
groups.google.com/group/
cloud-computing-use-cases.
• Version 1 of the paper is available
at bit.ly/1FXRAH.
bit.ly/1FXRAH
46

Developer requirements
• Scalable Database
• Centralized Logging
• Scalable Session Management
• Identity Management
• Robust Storage • Raw Compute / Job Processing
• Messaging – Pub-Sub • Service Discovery
• Messaging – Point-to-Point • SLAs
• Mail
• Caching What else?
47

Thanks!
By Doug Tidwell, Cloud Computing Evangelist, IBM
dtidwell@us.ibm.com