Tag: docker

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nginx + php5-fpm response lag on first requests

I’m in the middle of migrating this existing site to Docker containers and moving to a new VPS host. Part of my motivation for the move is to capture the customized configs for each of the servers, so I can easily move the whole deployment between a test environment and a production deploy. What’s prompting this is the realization that the majority of the performance tweaks I made during the first native install I have captured in various blog posts here, but to recreate these install steps I would need to go back to each of those articles and get the details in order to repeat them elsewhere. That’s not a particularly repeatable process.

I’m close to switch from my current non-Docker install (here, as of 2/27/18) to my test install now running on Docker. I’ll share more about how that is configured in future posts, but I just wanted to capture one nginx + php5-fpm specific config that had me stumped for a few days.

There’s many options for configuring the worker processes for nginx and php5-fpm. php5-fpm itself has a number of modes that control how it manages it’s worker processes. By default the process manager is ‘dynamic’ (pm = dynamic). This creates processes to handle incoming requests based on the other related config options (max_children, start servers, min_spare_servers, max_spare_servers etc).

On my current site based on recommendations I changed this to pm = ondemand in order to minimize memory usage on my 512MB VPS. One other param though had an interesting effect:

pm.process_idle_timeout = 10s;

This keeps a process alive for an additional 10s after it’s finished the current request. This seems to have an impact on the responsiveness of the WordPress site, as without this there seems to be a noticeable lag of 3-4 seconds before responses start to come back to the browser, presumably because new worker processes are needed to restart to handle the next request – by keeping them up after the last request there no lag to restart a new process.

I was almost at the point of making a no-go decision based on the laggy performance, but adding this one param has fixed the laggy behavior, and now I’m looking all set. Given that I’ve jumped from a 512MB VPS to a 4GB VPS, I’m less concerned about keeping memory usage to a minimum this time so I haven’t changed from dynamic to ondemand in the Docker config for my new nginx + php5-fpm config, but this one param is worth knowing about.

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Moving my nginx+mysql WordPress VPS native install to Docker containers on a KVM VPS

My WordPress blog that you’re reading right now is running on nginx and MySQL installed on a cheap OpenVZ VPS. I’ve been running on a $2.50 VPS from Virmach for the past 6 months or so and been very happy with the service. I spent a bunch of time tweaking the nginx and MySQL config params to run in < 512MB, which it does comfortably, but nginx and MySQL are both installed directly on the Ubuntu VM instance and it would be great of I could make this setup more easily movable between cloud providers (or even to have a local copy of the setup for testing, vs the live site).

I’ve been spending a lot of time playing with Docker and Kubernetes, so it seems logical that I should move the site into containers and then this will allow me to explore other deployment options.

Migration Steps – find a KVM VPS

As far as I know you can’t install Docker in an OpenVZ virtualized VPS container, so first step I need to move to a KVM based VPS so I can install Docker (and possibly Kubernetes). I’ve been shopping the deals on lowendbox.com and there’s plenty of reasonably deals for around $5/month for various combinations of 2 to 4GB RAM and 2 to 4 vCPU.

Dockerize nginx, MySQL and WordPress

I’ve been playing with this already. I’ve picked up my own combo of favorite/useful WordPress plugins, so I’ll probably share a generic set of Dockerfiles and then leave it up to anyone if they want to use them to customize your own WordPress install in the container.

Configure a local dev/test environment Docker setup vs production environment Docker setup on my VPS

This makes a lot of sense and is a benefit of using containers. This will allow me to test my config locally, and then push to my production node. I’ve been looking at using Rancher to help with this, but still got lots to learn.

More updates to come as my project progresses.

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Revisiting AWS ECS: deploying Docker containers to ECS

A few months back I walked through the steps to build, tag and deploy Docker containers to AWS ECS. It’s been a while and I need to revisit the steps.

Although you can use the the AWS Console, using the aws cli works well complements the common steps with the docker cli.

The steps you need to connect and login the docker cli to aws are listed from the AWS ECS dashboard, from the Repositories tab. Press the ‘Push Commands’ button and it will show you the login command which looks like this:

aws ecr get-login --no-include-email --region us-east-1

and the output shows you a ‘docker login’ command – copy this and paste it to where you run your aws cli, to logon on aws.

Assuming you have a docker image already built (‘docker build -t yourimage .’), then you can tag it ready to push with the next command listed from the ‘Push Commands’ output:

docker tag yourimage:latest id-of-your-ecs-registry.dkr.ecr.us-east-1.amazonaws.com/yourimage:latest

Now push with:

docker push id-of-your-ecs-registry.dkr.ecr.us-east-1.amazonaws.com/yourimage:latest

 

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Building and deploying a Monero crypto currency miner in a Docker container … running on a Kubernetes cluster

Updated: 1/30/18: Thanks to Max for the comment asking how your wallet id is passed to the miner – the Kubernetes deploy yml file example was cut off at the end and missing the args. Updated the example to show the correct args passed, including your wallet address.

Disclaimer: I don’t claim to be an expert in crypto currency and/or mining, my interest is purely a curious interest in the technology. Please don’t interpret anything here as an endorsement or a recommendation. Is it profitable to mine any currency with a spare PC? Probably not. Are some currencies profitable to mine? Possibly, with some investment in appropriate hardware. Please do your own research before you make your own decisions.

Knowing that some currencies like Monero can be mined with CPU based mining scripts alone, I wondered what it would look like to package a miner as a Docker image, and then run it at scale on a Kubernetes cluster. As you do, right?

First, I followed a Monero getting started guide to pull the source and build a suggested miner, then captured the steps to build the miner as a Dockerfile like this:

FROM ubuntu:17.10

#build steps from https://www.monero.how/tutorial-how-to-mine-monero
RUN apt-get update && apt-get install -y git libcurl4-openssl-dev \
 build-essential libjansson-dev autotools-dev automake
RUN git clone https://github.com/hyc/cpuminer-multi
RUN cd /cpuminer-multi && ./autogen.sh && ./configure && make
WORKDIR /cpuminer-multi
ENTRYPOINT ["./minerd"]

This Dockerfile contains the steps you’d follow to pull the source and build locally, but written to build a Docker image.

Next,  build and tag the image with the ip of your local Docker repo, ready for deploying to your Kubernetes cluster:

Build the image:

docker build -t monero-cpuminer .

Tag and push the image (192.168.1.80:5000 here is my local Docker Repository) :

docker tag monero-cpuminer 192.168.1.80:5000/monero-cpuminer
docker push 192.168.1.80:5000/monero-cpuminer

Before we start the deployment to Kubernetes, let’s check kubectl on my dev laptop can reach my Kubernetes cluster on my rack server:

kubectl get nodes --kubeconfig ~/kubernetes/admin.conf 
NAME                  STATUS    ROLES     AGE       VERSION

unknown000c2960f639   Ready     master    50d       v1.8.1

unknown000c297262c7   Ready     <none>    50d       v1.8.1

unknown000c29ab1af7   Ready     <none>    50d       v1.8.1

Nodes are up and ready to deploy.

Following the example .yml deployment file here, here’s my Kubernetes deployment file:

apiVersion: apps/v1beta2 # for versions before 1.8.0 use apps/v1beta1
kind: Deployment
metadata:
  name: monero-cpuminer-deployment
  labels:
    app: monero-cpuminer-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: monero-cpuminer-deployment
  template:
    metadata:
      labels:
        app: monero-cpuminer-deployment
    spec:
      containers:
      - name: monero-cpuminer-deployment
        image: 192.168.1.80:5000/monero-cpuminer
        args: [ "-o", "stratum+tcp://monerohash.com:3333", "-u", "your-wallet-id" ]

The args passed to the container are (scroll to the right above):

args: [ “-o”, “stratum+tcp://monerohash.com:3333”, “-u”, “your-wallet-id” ]

I’m using the monerohash.com mining pool – you can checkout their settings here.

Now let’s deploy with:

kubectl apply -f cpuminer-deployment.yml --kubeconfig ~/kubernetes/admin.conf

Listing the pods we can now see the two we requested starting up:

kubectl get pods --kubeconfig ~/kubernetes/admin.conf

And we can check the status and other info about the deployment config with:

kubectl describe deployments monero-cpuminer-deployment --kubeconfig ~/kubernetes/admin2.conf

This shows my required replicas available:

Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable

Now let’s scale it up to 4 replicas:

$ kubectl scale --replicas=4 deployment/monero-cpuminer-deployment --kubeconfig ~/kubernetes/admin2.conf 

deployment "monero-cpuminer-deployment" scaled

Replicas:               4 desired | 4 updated | 4 total | 4 available | 0 unavailable

Scaling up from 2 pods, to 4, then 8, we’re at about 75% of available CPU in my 2x Xeon HP DL380 rack server:

Fan speeds have ramped up from idle, but still comfortably running:

Hash rate so far:

So is it possible to run a Monero miner in Docker containers? Sure! Can you deploy to a kubernetes cluster and scale it up? Sure! Is it worthwhile? Probably not, and probably not profitable, unless you’ve got some spare low power consuming hardware handy, or something custom built to provide a cost effective hash rate depending on your power consumption and local utility rates. Still, personally this was an interesting exercise to check out building a Monero miner from source, and how to package it as a Docker image and deploy to Kubernetes.

Leave me a comment if you’ve done something similar and what hash rates did you get?

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