IaaS or “Infrastructure as a Service” is a concept and frequently offered product in the Cloud Computing space that currently appears to have as much pervasiveness as any of the other service types. What you wind up with, in the majority of cases, is an operating system running on a clustered hypervisor architecture. So – to the end-user or customer, it’s just like having a dedicated server – Perhaps with some added perks like only paying for computing resources used or High Availability at the hypervisor level, insulating your operating system from some hardware failures, etc.
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Posted in Architecture, Cloud Computing, J2EE, Java, Linux, Oracle
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Tagged Cloud, hypervisor, IaaS, PaaS, SaaS, Security, SOA
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You’ve probably heard about the recent disaster in Haiti. The Abstract Initiative team have been working with a variety of organizations to assist with this tragedy.
Please consider helping in this, their darkest hour.
If you are an organization that is working to help the situation in Haiti (or anywhere for that matter) Please send us an email if you believe we may be able to help.
Links:
http://www.redcross.org/
http://www.yele.org/
http://www.fh.org/
Thank you.
If you want to mount a file system read-only (for this example, let’s say the gpfs file system is named ‘bob‘):
echo ‘ro’ > /var/mmfs/etc/localMountOptions.bob
(remember, ‘bob’ is the name of the fs) – restart gpfs on that node.
If you want to prevent a node in a GPFS cluster from auto-mounting a specific file system: (file system named bob again)
echo “thisissometext” > /var/mmfs/etc/ignoreStartupMount.bob
The thisissometext doesn’t have to be anything specific, you just need to create a file with something in it.
The REAL gpfs documentation is available here: http://publib.boulder.ibm.com/infocenter/clresctr/vxrx/index.jsp?topic=/com.ibm.cluster.gpfs.doc/gpfsbooks.html
you set lock_sga=true didn’t you?
This doesn’t appear to be documented many places, so I’ll put it here. There can be a tangible performance increase to ‘locking’ SGA to pinned memory. Paging spaces are, after all, on a slower medium (disk). In AIX 5.3 you also need to ‘pin’ shared memory. (SGA is shared memory)
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Posted in AIX, Oracle, Tuning, UNIX
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Tagged ORA-27126
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With the increased popularity of older object oriented languages, and the increased pervasiveness of newer ones there is also an increased practice of using exceptions in place of checking return values. This is commonly seen in J2EE apps, and increasingly seen in PHP applications.
While I am in no position to tell you how to write your applications or how to do your job, here are some things to consider…
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Posted in J2EE, Java
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Tagged GOTO
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