dkhenry

Row Level Locks Interacting with Gap Locks

Here is a simple example meant to show how a row level lock can conflict wiht a `gap lock` and cause unexpected locking behavour

Create the Base Schema

For this we will use a very basic schema a simple table with a timestmp and condition.

BEGIN;
CREATE TYPE ProcessStep AS ENUM('submitted','completed');

dkhenry

---
apiVersion: "planetscale.com/v1alpha1"
kind: "PsCluster"
metadata:
  name: "example"
spec:
  containers:
    vtgate: "registry.planetscale.com/vitess/base:beta"
    vttablet: "registry.planetscale.com/vitess/base:beta"
    mysql: "registry.planetscale.com/vitess/base:beta"

dkhenry

#!/bin/bash
yum -y update
yum -y install jq docker
systemctl start docker
systemctl enable docker
packet-block-storage-attach -m queue
mount -t ext4 /dev/mapper/volume-14171d6f1 /data
/data/startup.sh

dkhenry

---
apiVersion: vitess.io/v1alpha2
kind: VitessCluster
metadata:
  name: superawesomecluster
  labels:
    app: vitess    
spec:
  lockserver:
    type: etcd3

dkhenry

execve("/usr/local/bin/cargo", ["cargo", "build"], [/* 56 vars */]) = 0
brk(0)                                  = 0x7f2d717cd000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2d6fba4000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=49275, ...}) = 0
mmap(NULL, 49275, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f2d6f4a8000
close(3)                                = 0
open("/lib64/librt.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\"\300\2719\0\0\0@\0\0\0\0\0\0\0\250\256\0\0\0\0\0\0\0\0\0\0@\0008\0\t\0@\0*\0)\0\6\0\0\0\5\0\0\0@\0\0\0\0\0\0\0@\0\300\2719\0\0\0@\0\300\2719\0\0\0\370\1\0\0\0\0\0\0\370\1\0\0\0\0\0\0\10\0\0\0\0\0\0\0\3\0\0\0\4\0\0\0\20R\0\0\0\0\0\0\20R\300\2719\0\0\0\20R\300\2719\0\0\0\34\0\0\0\0\0\0\0\34\0\0\0\0\0\0\0\20\0\0\0\0\0\0\0\1\0\0\0\5\0\0\0\0\0\0\0\0\0\0\0\0\0\300\2719\0\0\0\0\0\300\2719\0\0\0\30d\0\0\

dkhenry

This uses systemd to control a play2 service

I also am including the git-deploy configuration to update and restart the service from a devleopment machine

• play2.service

  The SystemD script Place in /etc/systemd/system/

• after_push

  The after push configuration file > goes in /deploy

dkhenry

import com.mongodb.casbah.Imports._
/**
 * Scheme has this general format ( amongst other fields )
 * { "_id" : ObjectId("5138c8bd5e0ee06dd30a6ee1"),
 *   "LAST_SIZE" : NumberLong(200),
 *   "SYMBOL" : "AAPL", 
 *   "LAST_PRICE" : 428.31, 
 *   "TOTAL_VOLUME" : NumberLong(8923961),
 *   "TIMESTAMP" : ISODate("2013-03-07T17:05:01.144Z"), 
 *}

dkhenry

# Install the build deps
sudo yum install --enablerepo=updates-testing --skip-broken gcc-c++ protobuf-compiler protobuf-c protobuf-c-devel protobuf-devel boost-devel openssl-devel v8-devel gperftools-devel nodejs npm curl ctags-etags m4 rubygems protobuf-static boost-static

# install the ruby deps
sudo gem install ruby_protobuf

# install npm manuall ( yum is broken currently )
git clone https://github.com/isaacs/npm.git
cd npm
make 

dkhenry

[Unit]
Description=Play2 Server for <site>
After=network.target
 
[Service]
Type=simple
PIDFile=<path>/RUNNING_PID
 
ExecStartPre=/bin/sh -c 'cd <path> ;/bin/rm RUNNING_PID ; sbt clean compile stage'
ExecStart=<path>/target/start

dkhenry

<?php
/**
	Program to upload data to SevOne using the Deferred Data API 

	@author DK (dkozlowski@sevone.com)
	@version 0.1
	@since 27-June-2012 
*/

//! The Appliance IP