Skip to main content

Message queue, SOA, and TTL

In a previous post I proposed using a database connection proxy in order to improve security. There are a number of other reasons why this is a good approach.

First line of defense routing transactions - if the application is connected directly to the DB then the application needs to add software that allows it to switch from primary to alternate DBs. This would essentially add unnessary complexity to the application. (simple is better). By creating a proxy the ability to switch traffic in a coordinated fashion will have many benefits.

Capacity and monitoring - Most databases do a lot to queue transactions from the client. That capacity is typically wellknown to the DB vendor, however, they never take into account the amount of other production events. For example there might be some extra disk I/O taking place on the DB server that the vendor would not be able to account for. Furthermore monitoring is limited to the vendors tools and nothing that you'd be able to improve upon. Using the proxy as a funnel it makes monitoring and metrics easier.

TTL (time to live) - One complication is the TTL. When transactions are queued and the DB server is busy certain transactions may appear to timeout. Therefore measuring the TTL will be important. Most DB servers provide a deadlock timeout, however, that is different than the customary TTL.

Supplementing or replacing stored procedures - in addition to stored procedures many transactions need more compute power but since the dataset is too large or the number of roundtrips is too high then putting the "transaction" in the proxy would provide many benefits of running the full application on the DB server.

Queues can help SLA When restarting DB - from time to time the DB server needs to be restarted.  This is terrible. In some cases the DB Server can be restarted in very few seconds but since the proxy has an incoming queue those transactions can be suspended while the DB connectivity is restored.

Impeadance options - when transitioning from DB vendor to another there are always a number of complications as the impeadence changes during the switch. There is also a disconnect between the code and the data. Proper implementation in the proxy layer gives you more choices.


Popular posts from this blog

Entry level cost for CoreOS+Tectonic

CoreOS and Tectonic start their pricing at 10 servers. Managed CoreOS starts at $1000 per month for those first 10 servers and Tectonic is $5000 for the same 10 servers. Annualized that is $85K or at least one employee depending on your market. As a single employee company I'd rather hire the employee. Specially since I only have 3 servers.

The pricing is biased toward the largest servers with the largest capacities; my dual core 32GB i5 IntelNuc can never be mistaken for a 96-CPU dual or quad core DELL

If CoreOS does not figure out a different barrier of entry they are going to follow the Borland path to obscurity.

UPDATE 2017-10-30: With gratitude the CoreOS team has provided updated information on their pricing, however, I stand by my conclusion that the effective cost is lower when you deploy monster machines. The cost per node of my 1 CPU Intel NUC is the same as a 96 CPU server when you get beyond 10 nodes. I'll also reiterate that while my pricing notes are not currently…

eGalax touch on default Ubuntu 14.04.2 LTS

I have not had success with the touch drivers as yet.  The touch works and evtest also seems to report events, however, I have noticed that the button click is not working and no matter what I do xinput refuses to configure the buttons correctly.  When I downgraded to ubuntu 10.04 LTS everything sort of worked... there must have been something in the kermel as 10.04 was in the 2.6 kernel and 4.04 is in the 3.x branch.

One thing ... all of the documentation pointed to the wrong website or one in Taiwanese. I was finally able to locate the drivers again: (it would have been nice if they provided the install instructions in text rather than PDF)
Please open the document "EETI_eGTouch_Programming_Guide" under the Guide directory, and follow the Guidline to install driver.
download the appropriate versionunzip the fileread the programming manual And from that I'm distilling to the following: execute the answer all of the questio…

Prometheus vs Bosun

In conclusion... while Bosun(B) is still not the ideal monitoring system neither is Prometheus(P).


I am running Bosun in a Docker container hosted on CoreOS. Fleet service/unit files keep it running. However in once case I have experienced at least one severe crash as a result of a disk full condition. That it is implemented as part golang, java and python is an annoyance. The MIT license is about the only good thing.

I am trying to integrate Prometheus into my pipeline but losing steam fast. The Prometheus design seems to desire that you integrate your own cache inside your application and then allow the server to scrape the data, however, if the interval between scrapes is shorter than the longest transient session of your application then you need a gateway. A place to shuttle your data that will be a little more persistent.

(1) storing the data in my application might get me started more quickly
(2) getting the server to pull the data might be more secure
(3) using a push g…