TIMER takes up to 4 arguments:

• 1st, the SQLScript to call.
• 2nd, an optional SQLScript to call when the primary script finishes or is cancelled.
• 3rd, the number of  milliseconds secondsto wait between each call to the primary script, defaults to 1.
• 4th, the mode of the controlling user form; MODELESS (the default) users may continue to navigate about the workbook or MODAL, the user must exit the form before any access is allowed to the workbook. Note: in MODELESS mode, if the user attempts to change any workbook cells, the TIMER (and any other TIMERs running) will stop.

So how to demonstrate TIMER in action?

I thought I’d set my sights to a further horizon, leave the humble laptop behind; I’d go all modern and use the cloud.

A conversation with Giles Thomas of  Resovler One and now Dirigible fame (the first a desktop Python-power spreadsheet, the other a cloud-based one), lead to my discovery of PiCloud. This is an Amazon EC2 based service that allows the execution of Python code remotely; handling all the messy business of provisioning of servers and marshalling of code and results.

It is not only easier than using EC2 directly but can also be much cheaper to use, as PiCloud charge by the second (rather than EC2s “use any portion of an hour, pay for the full hour” payment terms).

I thought I’d give it a go.

I used the same data and web site as Daniel Ferry’s VBA ‘threading’  example; a list of properties to check against the realestateabc.com “What’s your home worth?” site; returning various bits of information such as estimated value, size, last sale date and price achieved etc.

Being Python I used the wonderful Beautiful Soup package to extract the needed data from the site’s HTML. I also submitted a separate request for each property, but if this were for real, I would most likely submit fewer jobs to handle multiple properties as most of the cost of each job in this example was probably due to set-up and tear down rather than the url fetching and parsing. Not to mention the time to submit 100 jobs in the first place.

Above you can see the two SQLScripts involved. The LaunchCloud script submits the jobs and makes a call to TIMER to run the CloudChecker script every second. The CloudChecker script checks for results from PiCloud and pastes them back to the source table. When no more results due, it issues a STOP command which forces the TIMER to stop.

Above is the pyGetDetails script which is passed to PiCloud (via the cloud.call() statement) to do the actual fetching and parsing of the URL associated with each property.

Download latest version of microETL here. The workbook is called PiCloud (2007/2010 format), requires Python 2.7 and a subscription to PiCloud.

When first announced, I believed 64bit Excel would only be of interest to a minority of demented quants in investment banks hacking their way to yet another evil model to bankrupt the world. The problem of incompatible add-ins, COM controls etc. would also make its widespread adoption less likely.

But three things changed my mind:

• first, the appearance of Windows 7 powered 64-bit PCs on many worker’s desks
• second, my embedding of SQLite into Excel which enables me to effectively use the extra memory available to a 64-bit instance to hold, analyse and transform a huge amount of raw relational data (in the form of a “:memory:” database)
• and finally, the arrival on the scene of PowerPivot.

Although a PowerPivot workbook doesn’t allow more than 4Gig of memory to be addressed (this is a SharePoint restriction, as a 4G workbook is likely to compress down to <= the 2G upload limit imposed by SharePoint), this represents a doubling of the 32bit limits in memory terms, but much more in raw data terms as PowerPivot can achieve up to 10x-20x times data compression.

So, I decided to bite the bullet; fired up an AWS 64-bit image and started to upgrade my xLite code-base to handle this new world.

I decided on the TDN-GCC MinGW-w64 distro to re-compile 64-bit versions of my SQLite wrapper  libraries, and set about converting  my VBA code to handle both 64-bit and 32-bit dlls. So far, easy peasy.

The problems started when I went to convert my JavaScript & Python wrappers. I couldn’t get JSDB to compile to either 32-bit or 64-bit using MinGW-w64, so I abandoned the attempt as my main use of JSDB is as a “command-line data-crunching tool” similar to, and used along side, CSVFix and SFK (Swiss File Knife). Having the ability to call JavaScript in-process was relatively new and I could live without it.

More worrying was the problem with Python embedding, in-process Python would be harder to live without. The APSW SQLite library which I had used is 32-bit only. Luckily the Python 2.7 version of its SQLite3 standard module  (aka pysqlite) now allows the loading of SQLite C extensions. This enables me to load databases under Python and extract the C handle using a specially written extension, thus enabling Excel/VBA to attach to a Python opened SQLite shared memory.

Without this new  loaded extension trick I would have had to modify the SQLite3 library itself as the previous 2.6 version would not divulge SQLite’s handle, while APSW did, which was  the reason I picked APSW in the first place.  As a result, xLite’s Python functionality now requires Python 2.7.

So the end result is a somewhat reduced-functionality xLite  (no in-process JavaScript, missing APSW functionality such as Python-based SQLite virtual tables), but running on the ultimate data-smithing platform:

• Excel 64-bit combining with
• the relational power of SQLite 64bit,
• the fast and easy scripting power of Python 64-bit,
• and topped off with the king of pivots, 64-bit PowerPivot.

A week well spent, I think!

Oh, I’ve also decided to rename the add-in to MicroETL. This is mainly to reflect the fact that xLite (SQLite embedded in Excel) is just one element within the tool. The  pure-VBA detached-ADO recordset functionality, embedded Python and xLiteScript elements can exist independently of xLite.  That, and I’m fed-up getting enquiries about X-Lite http://www.counterpath.com/x-lite.html and I own the http://www.microETL.com URL

Large companies and start-ups are comfortable in the world of Linux servers but most small companies are Windows to the core.  This may not be “right”, this may not be how it “should be”, but it is so.   Even within large companies, departmental computing is largely a Windows only enclave, with MS Office (and Excel in particular) as the backbone and MS SQL Server as the database of choice (or is that, no choice).

The other interesting thing is that my fear that EC2 SQL Server Standard instances would be licensed as per Oracle has not come to pass (Oracle while making a “big thing” of their recent EC2 cloud conversion, still insist on traditional licensing for EC2 database instances). SQL Server Standard is available on a pay-as-you-go model, brilliant!.

Even if running Win2003 as a server doesn’t catch your fancy and in fact you would much rather get rid of your existing Window’s laptop to be replaced by a cool new Apple Mac. Unfortunately you still need the ability to run Windows-only software, why not use EC2 as your on-demand pay-as-you-go Window’s desktop replacement?  Simply configure a Windows AMI with your required software (you may have to use something like this, if software is only available on CD); you could then use Jungle Disk to easily share data (via S3) between your new shiny Mac and the AMI.  Power up and down as required, easier than using VMWare or Parallels and @ 12.5c per hour, probably cheaper too.

From my point of view, as with Oracle’s announcement last week, this releases yet more of my “legacy” skillset for deployment in the clouds. Although I’ve been involved with  *nix servers for 20 years or so, as corporate servers became more locked-down (and removed to the control of 3rd party data centres) I lost day-to-day experience of using them; in latter years my main ‘hands-on’ platform was Windows, either my own PC or local departmental NT servers. Windows on EC2 will allow me to use a whole new set of Windows only software (e.g. RSSBus or XLsgen) and of course SQLServer.

The lack of SQLServer on EC2 has been a major problem for me as a datasmith; there’s an awful lot of data out there sitting in SQLServer databases, but currently if I need to “cloud burst” such datasets I would have to first extract the data to, say, csv files and then load the data on to a Linux compatible database. But with a SQLServer instance running in the cloud, I could simply use SQLServer’s native backup/replication tools.  No more need to download data to my “ground-based” PCs resulting in quicker turnaround and fewer data security risks.

On the licensing front,  I’m presuming that the OS licence will be on a pay-as-you-go basis, but what about SQLServer and other server products?  Will MS do an Oracle on it, i.e. require a traditional upfront use-it-or-lose-it payment or will they the go the radical (but I thing inevitable) path of a licence-by-the-hour. 

First RedHat, then Sun, then Oracle and now Microsoft; the mighty beasts of our industry have acknowledged there’s a new mighty beast on the prowl, dressed as a humble bookseller no less!

The post from the Right Scale folks gives a detailed overview of the new  Amazon ‘SAN storage in the cloud’ service, aka Elastic Block Store, aka EBS.  Alas, this particular cloud offering was a mirage, the post was subsequently removed (but can still be viewed on Robert Scoble’s Shared Items) it seems the post was a work-in-progress and not intended for publishing, yet!

Why was I so excited?  Amazon EC2 had two major shortcomings when it launched 2 or so years ago; the first, ephemeral IP addresses, was solved by the new Elastic IP feature; the second, ephemeral storage volumes (when you shutdown an instance the disks are wiped!) is due to be solved by EBS.  With both of these problems solved, EC2, already near perfect, would be perfect.

The article does a good job of explaining the new service…

EBS starts out really simple: you create a volume from 1GB to 1TB in size and then you mount it on a device on an instance, format it, and off you go. Later you can detach it, let it sit for a while, and then reattach it to a different instance. You can also snapshot the volume at anytime to S3, and if you want to restore your snapshot you can create a fresh volume from the snapshot.

The thing that caught my eye in the above paragraph was the snapshot facility.  Snapshots are to be stored on S3 via an EC2-specific incremental-snapshot API.  This means the volumes will come with a built-in back-up facility. This is important as EBS drives reside in one availability zone (that of the instance that they are mounted against) and do not have the data replication security offered by S3.  It also means that disk systems can be restored quickly and simply from snapshots without the overhead  (and bugs!) of writing an S3 specific incremental backup and restore utility.

Back to waiting…

UPDATE: 20th August

Wait over…

For most of my datasmithing career, I’ve had access to corporate Oracle databases and now with the availability of  Oracle10g  Express I can even run my own Oracle instances at home or on EC2.  The combination of a powerful SQL engine, expressive scripting language (PL/SQL) ,OS independence, web front-end (App Express) and the ability to communicate with Excel (via OO4O) made Oracle a natural fit for heavy-duty data manipulation.   But there was always one major problem, Oracle doesn’t play well with other data sources, necessitating a separate ETL bolt-on, which led me to play around with the likes of Kettle and Talend.  But having been seduced by these new shiny (and open source) “toys” I’ve found that rather than just been incidental add-ons they had the potential to totally replace Oracle.  The combination of Talend, SQLite and Groovy, is proving to be particularly magic.

So how will these three tools enable you to leave behind your Oracle past?

Talend (in its Java form) is a superb ETL tool, via JDBC is can access every database type on the planet, it has built-in web-service capability and access to a  multitude of APIs via its Java component for non-database data sources.  The addition of  Groovy makes the use of such Java APIs simpler and quicker and the same Groovy acts as a replacement for PL/SQL when a bit of “if-then-else” logic is required.  And although Talend offers a built-in option to plublish an ETL job as a WAR file exposing a SOAP web service, Java/Groovy also allows for the integration of the powerful, yet simple, Jetty API to embed a web server within Talend itself.  And all this for free, and better than free, open source.

So where does SQLite come in? And, didn’t you say that Excel integration was important, how will Excel communicate with Talend?

As very little corporate data is held in SQLite format, and Talend allows access to every major commercial/free database, the usefulness of SQLite might not be at first obvious.  But if you think of SQLite as a data cache, a fast and efficient local tabular datastore, with a powerful but well understood DSL (i.e. SQL) and a drop-dead-simple setup and backup regime (basically copying and creating files), maybe then you can see its attraction. The ability to extend the DSL by easily creating SQLite user defined functions (UDFs) within Talend using either Java or Groovy is also another powerful feature.

For example…

select customer_id, name,customer, sales_region, getpalodata(“SALES”,customer_id,”All Products”.”Total Sales”,”Euros”,”YTD”)  as customer_YTD, getpalodata(“SALES”,sales_region,”All Products”.”Total Sales”,”Euros”,”YTD”)  as region_total_YTD from list_of_top_customers;

… where getapalodata is a UDF that wraps calls to a Palo cube.

With this type of setup I can easily mix and match list/tabular data with multidimensional data points using SQL (something that Oracle also supports but only if you hand over a large wad of currency). In fact I can create a mini data warehouse, with Palo providing the pivot, ( as SQLite lacks star-query (or even multi-index query) support.)  SQLite would still host the conformed dimensions and the fact tables, but with the fact tables acting as feeds to Palo cubes, supporting finer-grained drill-throughs from cubes or for ad-hoc queries. This is powerful stuff, simple, free, powerful stuff.

… and the spreadsheet access?

A Talend sub-job such as this…

Talend Groovy Jetty web server

Example of Groovy code calling Jetty API

…would provide a simple RESTful (rather than SOAP) web service which could be accessed either with an Excel Web Query or via a VBA macro which would parse the result and allow for more control.  For example …

http://localhost:1234/sqlgateway?sql=select customer_id,name from all_customers&type=HTMLTable

… this would return a list of customers wrapped in an HTML table, or …

http://localhost:1234/job/extractProspects?Rep=JonesTom&Month=JAN&SourceCompany=AXA&type=HTMLTable

…this might call a Talend job called extractProspects, passing in JonesTom, JAN and AXA as context parameters, which would then return a list of prospects extracted from a feed supplied by AXA’s system.

What would the Talend job look like?

The job might operate something like this:

• It would run either on the client as a service or on a LAN based server (or on a remote server, with a SSH VPN (or Hamachi) to provide security).
• At start-up, do a bunch of ETL tasks, pulling data from remote sources and databases, transforming and aggregating data etc. Storing the resulting data in local SQLite databases.  It might also build Palo cubes or update larger enterprise databases.
• The job would then setup a Jetty web server and await requests for data.
• The requests might be a mixture of raw SQL or requests to run specific Talend transformations which would return a dataset directly to the calling client or maybe just acknowledge the request, queue it up for processing later, sending the resulting dataset by EMail or RSS feed when finished.
• At a fixed time the service would shut it self down and requeue itself for the next day’s workload.

… or nothing at all like that, and that’s the point, build what you need, add the levels of security (or none at all) that fits your situation, all within a open framework, with zero lock-in (okay, still using Excel, anyone for OpenOffice, Google Apps or Zoho?).  You don’t even need your own server, host it on an EC2 instance, (if you bring up an instance for 10/12 hours every working day, it would cost about $20/$25 a month).

Now tell me that doesn’t make sense?

Am I worried? No, but as I become more and more dependent on such services, perhaps I will, but then again at least I’ll not be alone.  WordPress.com and countless others will be using the same excuse to their customers and unlike Renginald Perrin who had a different excuse every day for his train’s late arrival…

Ep.1   “Eleven minutes late, staff difficulties, Hampton Wick.”
Ep.1   “Eleven minutes late, signal failure at Vauxhall.”
Ep.1   “Eleven minutes late, staff shortages, Nine Elms.”
Ep.1   “Eleven minutes late, derailment of container truck, Raynes Park.”
Ep.1   “Eleven minutes late, seasonal manpower shortages, Clapham Junction.”
Ep.2   “Eleven minutes late, defective junction box, New Malden.”
Ep.4   “Eleven minutes late, overheated axle at Berrylands.”
Ep.4   “Eleven minutes late, defective axle at Wandsworth.”
Ep.5   “Eleven minutes late, somebody had stolen the lines at Surbiton.”

I figure I need two ‘template’ AMIs, one containing the bare minimum of software, EC2 tools, Python, Perl and Java; the second loaded with the likes of Kettle, Talend, Hamachi VPN, OracleXE , Palo MOLAP Server and Palo ETL Server and a Gnome desktop accessible via VNC.

I’m deciding whether to use Centos or Ubuntu as the basis for one or both templates. I’m more familiar with Centos’s RedHat heritage but Ubuntu’s design goals of ease-of-use and ease-of-update appeal.  Since I was in the process of re-evaluating my EC2 builds I decided to also check out NX as an alternative to VNC. I had tried to install NX Server on a Fedora 4 instance a few years back, but had abandoned the effort having spent the best part of a day on it, reverting back to my VNC comfort zone.

This time I was able to use one of Eric Hammond’s Ubuntu AMIs with NX pre-installed.  Wow, what a difference! It’s much more responsive, even over my tempermental fixed wireless broadband connection. I also tried it using my backup ISDN line, again a huge improvement compared to using VNC. If you’re still using VNC to remotely access EC2 or any other remote server, you’ve got to check out NX.

… not yet, but Bill Hodak from Oracle has just opened a thread over on the Amazon AWS developer forums, looking for feedback on the use of Oracle in AWS projects. First there was Red Hat, then this week’s announcement from Sun and now Oracle; has Amazon managed to turn itself into the cloud provisioner not just for the hungry masses of start-ups and independent developers but for the technology elites?

As for using Oracle on EC2, yes please. Most of my datasmithing career has been spent behind the wheel of an Oracle database, the front-ends might have been Excel or some BI package, the end results might have been SAP master data take-ons or an Essbase cube, but the blood and guts were always Oracle. And this was before Oracle Apex – think what wonders could have been achieved if I had access to such a product in the past.

When EC2 first appeared I enthusiastically installed Oracle 10g Express, using a Hamachi VPN to tunnel the Apex front-end back to my PC (don’t ever expose an Oracle 10g server to the public internet, its architects assumed it would be used solely within the corporate firewall). I even used the power of Oracle’s redo logs to partially protect against the ephemeral nature of EC2′s disk storage.

It looked to me back then that EC2 could be an ideal hosting environment for Oracle Application Express (aka Apex, aka HTML DB), but for a few wee problems:

• It’s not absolutely clear whether the Oracle 10G Express database licence covers its use in a virtual environment (sometimes the restriction of one database per server is stated as one per machine), a few attempts to look for a definitive yeah or neigh on the product’s support forums elicited no response. I’m guessing its fair-usage, but confirmation would be nice.
• Oracle doesn’t appear to know what to do with Apex, you get the impression they’re afraid it’ll cannibalise its lucrative J2EE business.
• 10g Express is severely hobbled as a database, not just the 4GB per server (or is that machine), it’s lacking any sort of updating service, serious security flaws remain unpatched and username/passwords are sent in plain text; making it suitable (and then only barely) for use within a firewall or VPN.
• Once you outgrow Express, you’re into big money and even worse you might have to talk to a sales rep!

So what would I like to see Oracle offering on EC2? A paid AMI, preloaded with a variation of Express, minus the 4GB limit, with a “hardened” public internet facade, along with regular patches automatically applied. Optional add-ons…

• Various levels of support, fixed monthly charge perhaps.
• Ability to upgrade to the full Enterprise Editions, but again paid for via a combination of AMI hourly charges and optional month-to-month support charges.
• Ability to purchase once-off consultancy, both from Oracle and third-party suppliers.

I’m not holding my breath though…

Oh, if you’re confused over the various “Express” terms used in the above, don’t blame me, blame Oracle, I thing the poor branding profile (constant name changes, copy cat names) is an indication of Oracle’s lack of commitment to both products.

UPDATE Sept. 22nd 2208

Looks like the Oracle Cloud has arrived..

SimpleDB on the other hand is not boring, it’s an exciting new shiny thing that opens up a myriad of new possibilities; but first, I and the rest of the developer community, need to tool up and cast aside some of our cherished database design patterns (oh like, 3rd normal form, strong typing, joins, nothing major) and embrace a slightly different way of thinking, however, as much as I like a challenge, I also like to get things done.

That’s where EnterpriseDB’s new Postgres Plus Cloud Edition comes in, this is an Amazon Ec2/S3 hosted edition of their Oracle compatible PostgreSQL-based product that offers the scalability of SimpleDB but the familiarity of a traditional relational database. The “magic” is supplied by Elastra, who are also offering the same functionality against MySQL and standard PostgreSQL databases.

A Talend ETL job which I had been developing for a client, had been tested against a “normal” EnterpriseDB instance. This ETL job was part of a BI prototype trialling a Postgres Plus Cloud Edition (the new name for EnterpriseDB’s cloud offering) as the back-end database. So, I exported the job as a Java executable, fired up an EC2 instance, copied up the generated JAR files, changed the database’s hostname to that of the Postgres Plus “cloud” database, ran the ETL job and it worked. As I said, boring, nothing to report, it just worked.

Now you may be wondering what’s so special about these Elastra powered databases, surely EC2 is no different from any other Linux virtual machine, why not simply install a standard database? The problem with EC2, and it is a problem to those of us (i.e. practically every IT pro on the planet) who have come to expect highly reliable RAID backed disk storage, is the non-permanence of its disk systems.

When an EC2 instance is powered down or fails, the disk system is wiped!

That, combined with fixed (if generous) disk sizes (160GB, 850GB or 1690GB), means that often a clustered database environment is a necessity, adding considerably to the complexity. It’s this sort of complexity that SimpleDB and Elastra address.

The obvious use-case for both Elastra and SimpleDB is as data stores for OLTP applications but Elastra’s ability to handle S3-backed massive databases means the possibility of using EC2 as a data warehousing platform is also considerably strengthened. Although not obvious at first glance, SimpleDB could also act as an OLAP data store; SimpleDB massively indexed tuples as “sparse dimensions” pointing to S3 objects (SQLite databases?) that hold the fact data combined with dense/”partioning” dimensions (e.g. Time). Possible ? Yes. Fun to do? Yes. A solution that I can apply tomorrow? No, that’s why I’m glad EnterpriseDB and Elastra are delivery such a boring product!

UPDATE Ec2:

The other big EC2 missing – non-permanent IP addresses – has at last been addressed. EC2 now offers “Elastic IP Addresses”, addresses associated with an account not an instance. If the instance fails or is shut down, the IP address can either be immediately re-assigned to a new instance (no more waiting for Dynamic DNS propagation) or “reserved” for future use at a cost of USD0.01c per hour. Also, the new “multiple locations” facility puts the API changes in place to allow for location selection, hopefully a sign that we here in Europe will have “local” EC2 instances to match our European S3 buckets!

UPDATE EnterpriseDB:

It looks like IBM have invested in EnterpriseDB, possibly as a counter-weight against Sun’s acquisition of MySQL (EnterpriseDB’s targeting of Oracle’s customer base would also be an added benefit!).