Network problems between MongoDB nodes

PROBLEM:
MongoDB replica sets provide high availability through replication and automated failover. We have a cluster comprising three nodes: replicas "mentos-a" and "mentos-b", plus an arbiter. The problem is that every X seconds, the PRIMARY steps down and the cluster failover to the other node.

SOLUTION:
The way we detect a downed node is by a loss of heartbeats and heartbeat responses. Heartbeat responses time out after 10 seconds and then if we have not received a heartbeat from them in the past two seconds (they are sent every two seconds), we mark them as down. So it is common for the election process to take 10 seconds before it starts.

We can change the number of seconds that the replica set members wait for a successful heartbeat from each other. If a member does not respond in time, other members mark the delinquent member as inaccessible.
In the following example we will change the default 2 seconds heartbeat to 30 seconds

rs0:PRIMARY> cfg = rs.conf();
{
 "_id" : "rs0",
 "version" : 2,
 "members" : [
  {
   "_id" : 0,
   "host" : "mentos-a:27017"
  },
  {
   "_id" : 1,
   "host" : "mentos-b:27017"
  },
  {
   "_id" : 2,
   "host" : "mentos-c:27017",
   "arbiterOnly" : true
  }
 ]
}
rs0:PRIMARY> cfg["settings"] = { heartbeatTimeoutSecs : 30 }
{ "heartbeatTimeoutSecs" : 30 }
rs0:PRIMARY> rs.reconfig(cfg);
{ "down" : [ "mentos-a:27017" ], "ok" : 1 }
rs0:PRIMARY> rs.conf()
{
 "_id" : "rs0",
 "version" : 3,
 "members" : [
  {
   "_id" : 0,
   "host" : "mentos-a:27017"
  },
  {
   "_id" : 1,
   "host" : "mentos-b:27017"
  },
  {
   "_id" : 2,
   "host" : "mentos-c:27017",
   "arbiterOnly" : true
  }
 ],
 "settings" : {
  "heartbeatTimeoutSecs" : 30
 }
}

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Push/Pull to git repos without entering your credentials all the time

PROBLEM:
You need to enter your git credentials all the time when you pull/push

SOLUTION:
Well, do this...

nano ~/.netrc

# Put the following 8 lines in ~/.netrc file
# change "yourSecret" to the secret key you are using to pull/push (not your github login password)
# change "yourLogin" to the github login
# Note about a limitation: password in .netrc file should not contain spaces, since the .netrc file is parsed against spaces, tabs and new-lines

machine github.com
login yourLogin
password yourSecret
protocol https
machine api.github.com
login yourLogin
password yourSecret
protocol https

# set chmod permissions (600 - owner can read and write)
chmod 600 ~/.netrc

# try get latest from master (and see you don't need to enter your credentials)
git checkout master
git pull origin master

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Why skipping Windows 9 ?

PROBLEM:
Why Microsoft is skipping Windows 9 ?

SOLUTION:
One of the technical reasons is too many legacy apps don't use the correct versioning APIs.
You can see examples in the following Java legacy code:

See more details here and here. But before, you are welcome to press one of the ads in this page.. Thanks!