Unable to launch Android emulator in Mac / OSX

Mac OS broken emulator avd

First, make sure that the Intel HAXM is up to date. You update it by opening the SDK and selecting it in the list.

Then, on Mac, the Android SDK gets installed at: /Users/username/Library/Android/sdk/, therefore, you will need to run the script as sudo, as follows:

sudo sh ~/Library/Android/sdk/extras/intel/Hardware_Accelerated_Execution_Manager/silent_install.sh

If all goes well, the script prints the message: “Silent installation Pass!”

Then, restart Android Studio and run your app with the desired AVD.

Posted in Android Tagged with: , , , ,

8 best practices for microservices security

8 best practices for microservices security

There is virtually no situation in software architecture that entirely frees you from security considerations. With microservices, some issues become more distinct and a lot harder. However, there are also a few features of microservices that can bolster security.

With microservices, the network is still a bottleneck. Things like access control, which the industry already understands thoroughly within the realm of monolithic applications, assumes a new, almost unexpected, level of complexity. This paves the way for debates and scrutiny over whether a microservices architecture actually solves more problems than it creates. Your decision to use microservices should always be conditional.

When you’ve done your due diligence and decided that microservices are right for you, it’s time to make sure that all of your applications’ security demands are met. Here are eight best practices for securing your microservices. Read more ›

Posted in Servers, Services Tagged with: , ,

Symfony security annotation on controller class and inherited action method

Symfony security extension annotation class and methodThis is a quick code example on how to extend the Symfony security extension in your bundle so you could have rules on the controller’s class as annotation and also inherit those and merge with the action method annotations.

namespace AppBundle\Configuration;

 * @Annotation
class Security extends \Sensio\Bundle\FrameworkExtraBundle\Configuration\Security
    public function getAliasName()
        return 'app_security';

    public function allowArray()
        // allow nested configuration (class/method).
        return true;

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Posted in PHP, Symfony2 Tagged with: , , ,

ElasticSearch Nested Filter Not Matching Emails

no match elasticsearch email filter uax tokenizerThere’s one situation where we need to help ElasticSearch to understand the structure of our data in order to be able to query it fully – when dealing with arrays of complex objects.

ElasticSearch has one great feature that it allows us to search in nested properties of complex JSON objects. It’s normally used for list of objects inside the parent document. Just to mention I am using ElasticSearch 1.4 for legacy reasons. Here is an example of the model we have stored locally in ES: Read more ›

Posted in ElasticSearch, NoSQL Tagged with: , , , , , ,

MySQL not starting – unknown variable table_cache

Table open cache mysql upgrade errorI’ve upgraded my dev server to latest version of Debian. Everything was going smoothly until I’ve got an error from mysql-server that it cannot be installed due to an error. I checked few websites that I have there running and all of them were down. Checked the logs but nothing obvious was there, eventually I realised the MySQL process was not running at all which was understandable considering the previous failure to install myslq server. So this was my error:

[ERROR] mysqld: unknown variable 'table_cache=64'
[ERROR] Aborting

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Posted in Servers, Unix Tagged with: , , ,

Get All Files in Directory and All Child Directories

PHP walk recursively with iterator over all directories and filesI was playing with PHP the other day and was trying to fetch and rename 1000s of files I have stored locally on my machine. Seemingly PHP isn’t the best language to that operation Python or even BASH could do the job though it was nice to give it a try. So this is what I came up, simple and straightforward.

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Posted in PHP, Small Tips Tagged with: , , , , ,

Change default date for Jackson in Spring Boot application

Java date convert timestamp in iso8601 for json swagger jackson spring bootDates as a concept are seamingly simple and straight forward. Though in programming world those could be rather complex starting from format, representation, time zones, machine default configuration going through different calendars and date manipulations.

In this post I won’t to give a quick tip on handling dates in an application that I am building. It will be short post, I promise.

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Posted in API, Java, Small Tips, Spring MVC, Swagger Tagged with: , , , , , ,

Swagger and polymorphic type handling with Jackson

polimorphic types with jackson and swaggerPolymorphic type handling based on JSON property

Building an API that supports inheritance could be quite crucial. Imagine the case where you want to have an endpoint that stores a profile data for a given provider and that provider could be your main website or any 3rd party platform that can provide the data. We might have a base Profile class which in our case would be abstract class with firstName and lastName fields and an abstract method to provide the name of the actual profile provider getProfile().

You can do all of that quite easily with few Jackson annotations, for  polymorphic types, on the base class and on the children that extend the base class. No more words here is an example: Read more ›

Posted in API, Java, Spring MVC, Swagger Tagged with: , , , , , ,

Spring Boot: Executing asynchronous method backed with a queue

Spring Boot - asynchronous execution of controller method with threading backed by a queueMany people go for different solutions and sometimes overcomplicate their applciation with message queues like ActiveMQ, RabbitMQ and other options out there. Though this is yet another part in the application architecture that would require maintenance and support and it’s also a possible failiure point.

There are good reasons to use this approach but in most cases you can get through with normal in-memmory queue with multi-threading. Read more ›

Posted in Java, Spring MVC Tagged with: , , , ,

Best practices in Agile Retrospectives

agile scrum retrospective meeting best practices dos dontsOne of the core Agile practices is to inspect and adapt. We inspect the developed software in the business review or demo meeting to ensure that we are delivering the right product. And we inspect how the team performs and interacts in the retrospective meeting to make sure that we are working in the right way and that we keep improving.

We should work on maximizing the benefits of the retrospective meeting and adapt according to its outputs, or it will turn into a useless ritual.

In this article, I share some tips on things you can do to improve your retrospective meetings, and things you should avoid as well.
Read more ›

Posted in Project Management Tagged with: , , , ,