akiatoji

Suppress libxml2 version warning. Sometimes the wrong libxml2 version keeps getting loaded.

brew install libxml2 libxslt

Let's say above installed libxml2 2.9.9_2

bundle config --local build.nokogiri "--with-xml2-lib=/usr/local/Cellar/libxml2/2.9.9_2/lib --with-xml2-include=/usr/local/Cellar/libxml2/2.9.9_2/include"

akiatoji

# I always forget how to do this

git branch -r --merged | grep -v master | sed 's/origin\///' | xargs -n 1 git push --delete origin

akiatoji

-- Who is being blocked?
SELECT
  pid
     , usename
     , pg_blocking_pids(pid) AS blocked_by
     , query                 AS blocked_query
FROM pg_stat_activity
WHERE
  cardinality(pg_blocking_pids(pid)) > 0
;

akiatoji

Install conda

Install MiniConda.

Install dependencies

These are the go-to packages I use for Machine Learning/Geo/NLTK work.

conda config --add channels conda-forge   # look in .condarc and make sure this is the first one 

akiatoji

# Load the image into an array: image
image = plt.imread('some.jpg')

# Flatten the image into 1 dimension: pixels
pixels = image.flatten()

# Generate a cumulative histogram
cdf, bins, patches = plt.hist(pixels, bins=256, range=(0,256), normed=True, cumulative=True)

new_pixels = np.interp(pixels, bins[:-1], cdf*255)

akiatoji

(WIP)

Install mesa-libGL-devel Install openmpi openmpi-devel Make sure you don't have newer GCC/G++ (must be 4.8.5) Rmove default install Cmake Download Cmake 3.2 or higher and build install Download xgboost Build xgboost

akiatoji

AWS EC2 Memory and Disk monitoring/alert

AWS kind of sucks when it comes to monitoring Memory and Disk usage on EC2, as in they don't provide it out of the box. AWS instead gives you a set of perl scripts to do this via CloudWatch custom metrics.

Details are here:

Monitoring Memory and Disk Metrics for Amazon EC2 Linux Instances

The following is the actual steps used to get Disk/Memory stats into CloudWatch

akiatoji

In Cloud Console:

• Create load balancer
• Create Compute instances with network tag to use as load balancer target.
• Create health check

Create target pool

gcloud compute target-pools create extloadbalancer  --region $MY_REGION --http-health-check webserver-health

akiatoji

In GCP Console, create VPC networks named vpn-1 and vpn-2 in us-east1 and europe-west1

In Cloud Shell:

Create VPN gateways

gcloud compute target-vpn-gateways \
create vpn-1 \

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# Initializing DS418play with 4 x 6TB disks

# ssh to NAS as yourseld

# Check the RAID block device and tunable values

cat /proc/mdstat  # was md2.  Getting about 30M/s

# Get original values:
echo "speed_limit_max: `cat /proc/sys/dev/raid/speed_limit_max`" #=> 200000