Brunomachadob

Problem with multi threaded systems on GraalJS

This is an oversimplified example extracted from ThrustJS and it's server lib http to show the result when we try to use Apache Tomcat to serve an API, using Nashorn and GraalJS.

When we navigate to http://localhost:8778/servlet using GraalJS we get an exception:

java.lang.IllegalStateException: Multi threaded access requested by thread Thread[http-nio-8778-exec-1,5,main] but is not allowed for language(s) js.
	com.oracle.truffle.polyglot.PolyglotContextImpl.throwDeniedThreadAccess(PolyglotContextImpl.java:545)
	com.oracle.truffle.polyglot.PolyglotContextImpl.checkAllThreadAccesses(PolyglotContextImpl.java:464)

Brunomachadob

Research about pdf creation

How to create a PDF file with 15.000 pages, preferably with a Stream as an input and output, to prevent memory issues.

Name	Stream	Complexity (1-5)	Time (s)	Memory (mb)	O.P. (mb)
[pdfmake]	N	2	Infinite	500	None
[pdfkit]	Y	5	10	300	None
[pdfjs]	Y	3	18	700	None
[wkhtmltopdf]	N	HTML	83	100	300

Brunomachadob

version: '3'
services:
  mockserver:
    image: jamesdbloom/mockserver:mockserver-4.1.0
    command: /opt/mockserver/run_mockserver.sh -serverPort 9090 -Dmockserver.logLevel=WARN
    networks:
      envoygateway:
        aliases:
          - api
          - api-mirror

Brunomachadob

data class Request(
    val method: String,
    val path: String,
    val headers: Map<String, String>
)

class RequestBuilder {
    private lateinit var method: String
    private lateinit var path: String
    private var headers = mutableMapOf<String, String>()

Brunomachadob

This is a educational purposed implementation of the Diffie Hellman key exchange for encrypted conversation between two parties.

Do not use this in production (as it is simplifying a lot of stuff, despite I know you will ignore this)

If you use IntelliJ, you can just paste the implementation into a new scratch and run it.

Brunomachadob

This is a educational purposed implementation of the Onion Router specification for encrypted/annonymous conversation between two parties.

Do not use this in production (as it is simplifying a lot of stuff, despite I know you will ignore this)

If you use IntelliJ, you can just paste the implementation into a new scratch and run it.

Let me know in the comments if you have anything that could be improved (without adding too much complexity to it)

Brunomachadob

Envoy is changing the x-request-id version when we configure the connection manager with:

tracing: {}

I configured Envoy with the upstream cluster pointing to postman-echo.com which will return as response body, the request headers sent.

curl --location --request GET 'localhost:8080/headers' \
--header 'x-request-id: 968ea8f8-3806-45c9-8228-8d3dde5df3b4' \

Brunomachadob

Without the right query param:

○ → curl -v localhost:80/mge?serviceName=SessionManagerSP
*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 80 (#0)
> GET /mge?serviceName=SessionManagerSP HTTP/1.1
> Host: localhost
> User-Agent: curl/7.64.1