dhis2-devs team mailing list archive

[Knut Staring <knutst@xxxxxxxxx>]

I think we should get DHIS2  added to that list of systems (typically)
running on Tomcat. It is a MoinMoin wiki, so I thought I could just add us,
but it seems this is an "immutable" page..


On Sun, Sep 22, 2013 at 7:19 AM, Jason Pickering <
jason.p.pickering@xxxxxxxxx> wrote:

> Hi Thanh,
>
> First off, be sure you are aware of who you are dealing with in such a
> debate. These "commercial companies" are probably a lot better at you in
> selling products to people who do not need them than you are. This is after
> all, what they do. So, keeping that in mind, lets pick apart what they are
> saying.
>
>  "DHIS2 is not built on and use well-know reliable solutions such as
> Microsoft Sharepoint, IBM Websphere,  Oracle Bea Weblogic"
>
> No reason why you could not used DHIS2 with Websphere or Weblogic in
> theory. Of course, it would be a huge waste of money to plonk down money
> for these applications, when Apache Tomcat (which is free) will do the job
> just fine. DHIS2 is using Spring and not EJB, so there is simply no need
> for these products. As for Sharepoint, well, it is a totally different
> application stack, and not really interesting to debate about. Point is
> DHIS2 is built using Java and lots of standard open-source libraries used
> by lots of other projects (including commercial ones). So which application
> server it uses is really a mater of choice. You could take Tomcat, and it
> would work fine. You could also pay a company a lot of money for
> a licence for one of the products you mention.  Here is a partial list of
> companies/projects using Tomcat, and the number is not small (
> http://wiki.apache.org/tomcat/PoweredBy)
>
> >1. When multiple DHIS2 instances can be deployed in multiple servers
> (virtual or physical) and load balanced by a hard or soft balancer
> (nginxs), this can not solve the real >problem of distributed HTTP sessions
> like what can be done in Application Server, i.e. a logged in users
> connected to a instance and this instance die, how can they continue
> >without relogin.
> >Can using Application Server solve the problems without having to rewrite
> dhis2?
>
>
> Which Application Server? I guess my question here would be what is the
> impact of a clustered Tomcat instance crashing? OK, maybe the user has to
> login again. Maybe they loose a little bit of work at worst. So what? Not
> that this is not an impact, but would it justify even an attempt to
> implement a load-balanced clustered solution with some sort of failover
> protection transparent to the user? It would not really seem to be
> justified.
>
> >How are we going to solve this? Will we need to use commercial solutions
> like Terracotta BigMemory or IBM Data Grid?
>
> What is the point? This again sounds like a bit of a snake-oil argument
> here. These products are not going to help with the issue of an application
> server failing. .
>
> >3. I would like to know the typical deployment of dhis2 in other
> countries. Is that on one or multiple server, with or without database
> clusters? I heard that many countries go for >cloud but I am not sure if it
> is a single or multiple cloud servers?
>
> Most countries which I know of are using a rather modest server. Many are
> using the cloud, some are not. Many countries have everything on the same
> machine (database, application server, nginx) and separating the database
> and application server is fairly typical as well.  But I could imagine
> there are some installations out there which are using clusters, but I
> would say this is probably not typical (yet) of most DHIS2 installations.
>
>
> >Can cloud provide us a single virtual but unlimited RAM and CPUs server?
> As if yes, then we don't have to worry about question 1, 2 because we can
> simple add 10000000 >GB RAM and 100000 CPUs to that cloud server.
>
> Well, for all intents and purposes, you could continue to increase the
> size of the server up to a certain size as required but I think the metrics
> you give there are pretty ridiculous.Why would you need that much RAM or
> CPU power?  Even if it were physically possible which seems reasonable
> (although likely very very expensive) , it would generally not make much
> sense to do this. Probably better to break the system up into smaller
> pieces instead. Using many small servers to distribute the process is
> typically the favored approach, instead of having one big massive machine.
>
> Anyway, there are a few thoughts off the top of my head. In summary, there
> is simply no need for the commercial products you mention in the vast
> majority of use cases we have come across. Not to say that they do not
> exist, but I would press these "companies" for more details on how these
> are actual requirements, and not simply invented hypothetical cases which
> could potentially be used to make a sale of unneeded licences.
>
> Regards,
> Jason
>
>
>
> On Sun, Sep 22, 2013 at 3:14 AM, Ngoc Thanh Nguyen <
> thanh.hispvietnam@xxxxxxxxx> wrote:
>
>> Hi all,
>>
>> Some commercial affiliated companies want to kick dhis2 out so they made
>> the following arguments: "DHIS2 is not built on and use well-know reliable
>> solutions such as Microsoft Sharepoint, IBM Websphere,  Oracle Bea Weblogic"
>>
>> When most of this is wrong they have some valid points that we need to be
>> prepared in order to fight back. I would like to get your ideas on
>>
>> 1. When multiple DHIS2 instances can be deployed in multiple servers
>> (virtual or physical) and load balanced by a hard or soft balancer
>> (nginxs), this can not solve the real problem of distributed HTTP sessions
>> like what can be done in Application Server, i.e. a logged in users
>> connected to a instance and this instance die, how can they continue
>> without relogin.
>>
>> Can using Application Server solve the problems without having to rewrite
>> dhis2?
>>
>> How are we going to solve this? Will we need to use commercial solutions
>> like Terracotta BigMemory or IBM Data Grid?
>>
>> 2. For database scale, with one database instances installed on single
>> server. it has the risk of data loss. We can use database clusters to
>> address this issue, and data on clusters mostly rely on memory. My question
>> is how this cluster will work with distributed sessions described in
>> question 1.
>>
>> 3. I would like to know the typical deployment of dhis2 in other
>> countries. Is that on one or multiple server, with or without database
>> clusters? I heard that many countries go for cloud but I am not sure if it
>> is a single or multiple cloud servers?
>>
>> Can cloud provide us a single virtual but unlimited RAM and CPUs server?
>> As if yes, then we don't have to worry about question 1, 2 because we can
>> simple add 10000000 GB RAM and 100000 CPUs to that cloud server.
>>
>> Thanks in advanced.
>>
>> Thanh
>>
>>
>>
>>
>>
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>>
>
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>


-- 
Knut Staring
Dept. of Informatics, University of Oslo
+4791880522
http://dhis2.org