dvliman

concurrency-models

dvliman

Keybase proof

I hereby claim:

• I am dvliman on github.
• I am dvliman (https://keybase.io/dvliman) on keybase.
• I have a public key ASBe4DkFe9qsB1j_Dc89k_Vd2euOfMD-Qz4FXTtbNRwTtwo

To claim this, I am signing this object:

dvliman

Spike

I looked into the state of GraalVM and Clojure and wrote some small work-related scripts.

GraalVM Build Tools

• Downloaded GraalVM and set $GRAALVM_HOME
• Found two main libraries for building GraalVM CLIs - https://github.com/luchiniatwork/cambada#packaging-as-a-native-image and https://github.com/taylorwood/clj.native-image (or https://github.com/taylorwood/lein-native-image for the lein equivalent). I chose clj.native-image as it seemed more focused on doing one thing well.
• First tried its template example which was easy to follow.
• Then added a graalvm build to one of our small cli tools
• Found it to be pretty straightforward except for a stdout flushing issue that was trivial to fix

dvliman

Turning PostgreSQL into a queue serving 10,000 jobs per second

RDBMS-based job queues have been criticized recently for being unable to handle heavy loads. And they deserve it, to some extent, because the queries used to safely lock a job have been pretty hairy. SELECT FOR UPDATE followed by an UPDATE works fine at first, but then you add more workers, and each is trying to SELECT FOR UPDATE the same row (and maybe throwing NOWAIT in there, then catching the errors and retrying), and things slow down.

On top of that, they have to actually update the row to mark it as locked, so the rest of your workers are sitting there waiting while one of them propagates its lock to disk (and the disks of however many servers you're replicating to). QueueClassic got some mileage out of the novel idea of randomly picking a row near the front of the queue to lock, but I can't still seem to get more than an an extra few hundred jobs per second out of it under heavy load.

So, many developers have started going straight t

dvliman

package httplib

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"testing"


	"github.com/manyminds/api2go"

dvliman

set -gx PATH $PATH /usr/local/sbin
set -gx GOPATH $HOME/go
set -gx GOBIN $GOPATH/bin
set -gx PATH $PATH $GOBIN
set -gx GOOGLE_APPLICATION_CREDENTIALS /Users/dliman/lereta/acq-plt/app-credentials.json
set -gx GOGOOGLE_APPLICATION_CREDENTIALS /Users/dliman/lereta/acq-plt/app-credentials.json
set -gx APP_ENV local
set -gx PROJECT_ID ltf-eng-dliman-cb8b

function set_psql

dvliman

Time.now.strftime("%Y%m%d%H%M%S")

dvliman

# rename files to have underscores instead of ' ', '(', and ')' - runs on * or takes extension argument: i.e., `rename_filename_chars txt`
rename_filename_chars() { for file in *"$1"; do mv -n "$file" $(echo $file | sed -e "s/ /_/g" | sed -e "s/(/_/g" | sed -e  "s/)/_/g"); done }

dvliman

;; -*- mode: emacs-lisp -*-
(defun dotspacemacs/layers ()
  (setq-default
   dotspacemacs-distribution 'spacemacs
   dotspacemacs-enable-lazy-installation 'unused
   dotspacemacs-ask-for-lazy-installation t
   ;; If non-nil layers with lazy install support are lazy installed.
   ;; List of additional paths where to look for configuration layers.
   ;; Paths must have a trailing slash (i.e. `~/.mycontribs/')
   dotspacemacs-configuration-layer-path '()

dvliman

public static void main(String[] args) throws Exception {
    Security.addProvider(new BouncyCastleProvider());
    KeyPairGenerator keygen = KeyPairGenerator.getInstance("ECDH", "BC");
    keygen.initialize(ECNamedCurveTable.getParameterSpec("P-256"), new SecureRandom());

    KeyPair keypair1 = keygen.generateKeyPair();
    KeyPair keypair2 = keygen.generateKeyPair();

    String secret1 = computeSecret((ECPrivateKey) keypair1.getPrivate(), (ECPublicKey) keypair2.getPublic());
    String secret2 = computeSecret((ECPrivateKey) keypair2.getPrivate(), (ECPublicKey) keypair1.getPublic());