January, 2015 | The Buttonfactory

I got a 400Gb log file for my birthday today.

This 400gb made me mad, It’s just a temp db. And all processes are down this morning. Looking around on the internet, this seems to be a common known problem, some even state this problem is acknowledged by Microsoft.

After reading some blogs on possible solutions. I decided I need to solve the disk problem first. First checks you need to do before you start the troubleshoot:

You need to rule out that you didn’t bring this over yourself, the ReportTempDb needs to be in Simple mode, this means there are no logbackups and the it should automatically reclaim space in your logfiles, well, this is how it should work. But in this case the logspace keeps growing. Indicating something is wrong with the reportserver, when it already is in Simple mode.

Also It could be worthwhile to check which reports are costing you, since not only your log space is invaded by report servers, your CPU is probably a victim too..

SELECT 
	sd.ReportPath,
	COUNT(s.SegmentId) as CountOfSegmentId
FROM 
	[ReportServerTempDB].dbo.Segment s 
INNER JOIN 
	[ReportServerTempDB].dbo.ChunkSegmentMapping m 
ON 
	m.SegmentId = s.SegmentId
INNER JOIN 
	[ReportServerTempDB].dbo.SegmentedChunk c 
ON 
	c.ChunkId = m.ChunkId
INNER JOIN 
	[ReportServerTempDB].dbo.SessionData sd 
ON 
	sd.SnapshotDataID = c.SnapshotDataId 
GROUP BY	
	sd.ReportPath
ORDER BY 
	CountOfSegmentId DESC;

SELECT

sd.ReportPath,

COUNT(s.SegmentId) as CountOfSegmentId

FROM

[ReportServerTempDB].dbo.Segment s

INNER JOIN

[ReportServerTempDB].dbo.ChunkSegmentMapping m

m.SegmentId = s.SegmentId

INNER JOIN

[ReportServerTempDB].dbo.SegmentedChunk c

c.ChunkId = m.ChunkId

INNER JOIN

[ReportServerTempDB].dbo.SessionData sd

sd.SnapshotDataID = c.SnapshotDataId

GROUP BY

sd.ReportPath

ORDER BY

CountOfSegmentId DESC;

After these checks, we have 2 routes to go, but today we’ll will start with the quick and dirty one, solve the disk shortage, since all processes are put to a stop due to this ‘Stay Puft’ logfile. We need to shrink this beast, I should tell you, shrinking your database is pure evil and risk taking. You should never ever ever do this! …Unless even Microsoft says it’s ok. And it’s just tempdata. It should’ve just deleted itself.

First, we are gonna run a full backup of the ReportserverTempDb, to an external location, ofcourse. Once this is done, we canstart with the clean up of the logfile.

Bring your database level to full mode, this allows you to alter the filegroups.

Right click tthe ReportServerTempDb database Go to the option shrink –> files and check the available free space and check the release unused space button.

This should give you some space, in my case, 400Gb, whoohoo, Dobby is free! Don’t forget to put your ReportServertempDb back into simple mode!

You could also shrink the log file with the ‘shrink file’ option, but like I said earlier, it’s better to avoid this option, because it could lead to faulty logfiles when you need to recover. But I case of this ReportServerTempDb the risk is low.

Now that we have got some diskspace back, we need to dig deeper to find out the cause of this log file eating up all your precious disk space. Next topic will be how we can fix this Stay Puft log file growth.

Testing for the newbie

To test your Node API’s you will need to install the following dependencies:

Mocha. Mocha is a library to run tests, AKA a test runner, or test infrastructure. Install it globally, like so: npm install -g mocha.
Chai. With Chai you can use “assert that.. ” or “should be.. ” or “expect that.. “. Depends on the test philosophy you are using (BDD, TDD and the likes)
Superagent. Superagent is a library that can test a web api, like so: superagent.get(‘http://localhost:3001/food’)

Of course there are alternatives (Jasmine, Should ..) but in my humble experience the above 3 work just fine. At first I was wondering why I needed so many libraries but I guess this all about the freedom to mix and match the modules you like the most. Which is quite nice.

Test the API

This is an example test to the ‘list’ function of all the food. Does the API return a JSON array? Well, it should, so I expect it to be.

First, Create a folder named ‘test’
Then put a file in it. (e.g. test1.js), with these contents:

var superagent = require('superagent');
var chai = require('chai');
var expect = chai.expect;

describe("Food JSON api", function() {  

  it("should return a json array", function(done) {
    superagent.get('http://localhost:3001/food')
      .end(function(err, res) {
        expect(err).to.eql(null);
        expect(res.status).to.equal(200);
        expect(res.body.success).to.equal(true);
        expect(res.type).to.equal("application/json");
        done();
      });
  });

var superagent = require('superagent');

var chai = require('chai');

var expect = chai.expect;

describe("Food JSON api", function() {

it("should return a json array", function(done) {

superagent.get('http://localhost:3001/food')

.end(function(err, res) {

expect(err).to.eql(null);

expect(res.status).to.equal(200);

expect(res.body.success).to.equal(true);

expect(res.type).to.equal("application/json");

done();

});

}

Now run the test with the command: mocha.

[jacqueline@pc01 Restaurant]$ mocha

  Food JSON api
    ✓ should return a json array 


  1 passing (39ms)

[jacqueline@pc01 Restaurant]$ mocha

Food JSON api

✓ should return a json array

1 passing (39ms)

Another test

With SuperAgent you can also test a POST action (be sure not to use your production db, but more about different environments later).

it("should post a new piece of food", function(done) {
    superagent.post('http://localhost:3001/food/')
      .send({
        name: "awesome food in test db from env", description: "awesome food description", price: "16,00"
      })
      .end(function(err, res) {
        expect(err).to.eql(null);
        expect(res.body._id).to.not.be.eql(null);
        id = res.body._id;
        done();
      });
  });

it("should post a new piece of food", function(done) {

superagent.post('http://localhost:3001/food/')

.send({

name: "awesome food in test db from env", description: "awesome food description", price: "16,00"

})

.end(function(err, res) {

expect(err).to.eql(null);

expect(res.body._id).to.not.be.eql(null);

id = res.body._id;

done();

});

Run the test:

[jacqueline@pc01 Restaurant]$ mocha


  Food JSON api
    ✓ should return a json array 
    ✓ should post a new piece of food 


  2 passing (38ms)

[jacqueline@pc01 Restaurant]$ mocha

Food JSON api

✓ should return a json array

✓ should post a new piece of food

2 passing (38ms)

So, this was just a wee intro to testing web API’s. There is lots more to discover about this subject!

I just put the code online at github. This is still a work in progress though.

Month: January 2015

Report server log file eating up diskspace – ReportServerTempDb

Beginning Node.js – Testing – part 5

Testing for the newbie

Test the API

Another test