Database Clustering Tutorial 1 - Intro to Database Clustering — Transcript

Full transcript

1. 0:00What is up my peeps from the intertubes?
2. 0:02It's me from CalebTheVideoMaker2 and in this series we are going to be talking about database
3. 0:08clustering and managing those database clusters with a tool called ClusterControl.
4. 0:14A database cluster put simply is when you have multiple computers that are all used
5. 0:19to store your data.
6. 0:20I've come up with four reasons why database clustering is a good thing.
7. 0:25Those reasons are data redundancy, the good kind of data redundancy (and we will talk
8. 0:29about that in just a moment), availability scalability and monitoring.
9. 0:37Okay...
10. 0:38I need spell check this time.
11. 0:39The very first reason is data redundancy.
12. 0:43Now I've talked a lot about data redundancy in my videos and all through one of my series,
13. 0:48database design I talk about how data redundancy is really bad but, that is a different kind
14. 0:53of data redundancy.
15. 0:55That kind of data redundancy is when you have unnecessary duplicate data that can then...
16. 1:03one can change and one can stay the same for example and then you have ambiguity, because
17. 1:07you don't know if these are two separate entries or if they are talking about the same thing
18. 1:12and one of them is incorrect and it just gets really messy and confusing.
19. 1:17Data redundancy when it comes to database clustering is a little bit different.
20. 1:21So with database clustering we are essentially using three computers to store our data.
21. 1:26But how exactly is that data going to be stored?
22. 1:28Are we going to store a third of the data in each one of these computers or are we going
23. 1:33to store most of the data on one and then more important stuff on the other?
24. 1:37or what? or what?
25. 1:39Actually we are going to have these synchronize to where all of the computers store the same
26. 1:44information.
27. 1:46That's a great thing because if one of these computers blow up, well you still have two
28. 1:49copies of the data!
29. 1:51So this data redundancy is not a bad thing because everything is going to be synchronized.
30. 1:57What that means is that as soon as there is a change on one of these computers, that change
31. 2:01is going to propagate to all of the computers inside of this cluster.
32. 2:06The data being synced this way gets rid of the risk of ambiguity because all of the data
33. 2:11is going to be the same.
34. 2:12Data redundancy is one of the features you're not going to be able to get if you are just
35. 2:15using a stand alone computer for all of your data because then if this computer blows up,
36. 2:21goodbye all your data!
37. 2:22Or you are going to have to get regular backups and store them on a hard drive or on something
38. 2:26else.
39. 2:27But we don't want to do all that extra stuff.
40. 2:29We just want it so where if something catastrophic happens the data is not going to be deleted.
41. 2:35We don't have to worry about backing up data and all that stuff.
42. 2:39Obviously you should still back up your data but there is a whole new layer or protection
43. 2:44when you have a cluster.
44. 2:45Now when it comes to scalability, the thing I'm most interested in is load balancing.
45. 2:52What a load balancer does is it will take all of the incoming traffic and what it will
46. 2:58do (so let's say this big bubble is our load balancer) what the load balancer will do is
47. 3:03it will direct where the traffic should go to which node it should go.
48. 3:12The benefit of that is that well...
49. 3:13there is only one communication point to the database cluster, right here, so it's easier
50. 3:19for the programmer.
51. 3:20The second thing is that the load balancer is not going to tax one particular computer
52. 3:25too much.
53. 3:26So you can just think of it as balancing the demands all across these different computers
54. 3:31and not taxing one particular computer too much such that is slows down or explodes!
55. 3:39Worse case scenario....
56. 3:41When it comes to load balancing though, it can be a little confusing because there are
57. 3:45a lot of different competitors and options so not all of them work exactly the same way.
58. 3:50This is just a general example that will help you understand the concept of load balancing.
59. 3:56When it comes to scalability, that means that you can expand the application very easily.
60. 4:03If you are working with one computer for example and you just get like BOOM 4 million visitors,
61. 4:07well that might tax the system really bad.
62. 4:10With a load balancer those visits are going to be distributed and when you have spikes
63. 4:15of growth, your system is not pressured as much.
64. 4:20Scalability and availability go hand in hand.
65. 4:23Essentially what availability is, is how much or how often your application or database
66. 4:29is available.
67. 4:31How often are you able to use it and how often is it broken?
68. 4:36We want the availability to be as high as possible.
69. 4:39So for example let's say we have a 99 percent availability.
70. 4:43Well that seems pretty good.
71. 4:46I mean it's almost 100!
72. 4:47But if you think about it 1 percent of the time, your database is going to be unavailable.
73. 4:56So if you think of 365 in a year.
74. 5:0010 percent would be 36.5 1 percent would be 3.65 So we're talking 3 1/2 days that your
75. 5:10database is not going to be available.
76. 5:11So 99 percent is actually a really bad value.
77. 5:15How high of a number do you actually need?
78. 5:17That depends on what the database is being used for and how many users you're going to
79. 5:22be getting.
80. 5:23For example if a mom and pop shop can save some money by going to 99 percent and not
81. 5:28paying extra for that extremely high available, then 3 1/2 days down of the year isn't that
82. 5:34bad.
83. 5:35But if you're google, that's really not that good.
84. 5:41Scalability comes in because if you're load balancing, you're going to make your availability
85. 5:45much higher.
86. 5:46Because you know, this computer explodes, nothing breaks because you can communicate
87. 5:52with this computer just the same.
88. 5:54And with a load balancer, it understands all that so it knows which computers to talk to.
89. 6:00If you were just connecting right to this database here and then it breaks, that not
90. 6:07good because now until its fixed, your software systems not going to work.
91. 6:13That's bad!
92. 6:14The last thing is monitoring and automation.
93. 6:17I just clumped those together.
94. 6:19So let's make sure we are all on the same page.
95. 6:22When I'm talking about monitoring, I'm talking about looking at the health of your database
96. 6:27system.
97. 6:28You can do that manually, but there are a lot of tools out there to help you automate
98. 6:32the process.
99. 6:34So you can write scripts against your database cluster and say, "Hey!
100. 6:38If this is going on make sure you tell me because that's a big problem."
101. 6:42And you can have these scripts run regularly like once a week or once a day or every so
102. 6:46often and that will help you monitor the health of your database.
103. 6:51Also with automation (another piece of automation) is doing a lot of this database clustering....
104. 6:56[dog in background drinking water] Onyx will you be quiet!
105. 6:58I'm making a video!
106. 7:00You can do a lot of this database clustering automatically with some of the software tools
107. 7:04out there.
108. 7:05For example you can just say "Hey!
109. 7:07I want a load balancer."
110. 7:08Enable.
111. 7:09Boom!
112. 7:10You have a load balancer.
113. 7:11That's all you have to do.
114. 7:12We will be getting into some of those tools.
115. 7:15Until then, I just want to talk about theory.
116. 7:16So that is all I really have to talk about in this video.
117. 7:19In the next couple of videos will be some more informational stuff, and then what we're
118. 7:23going to do is actually make a database cluster.
119. 7:26That's going to be cool because then we can test stuff.
120. 7:29We can shut one down and see how things work and all that good stuff.
121. 7:33So this series is going to be sick!
122. 7:37That's good by the way...
123. 7:38That's kind of a dumb slang term because sick is like a bad things, but when you say something
124. 7:44is sick somehow it's a good thing... but who knows!
125. 7:47So just as some extra information to help you get through this series the best I'm going
126. 7:51to have a study guide available at the end of this video and also in the description
127. 7:56probably...
128. 7:57In addition to that I'm going to have extra information on my website CalebCurry.com which
129. 8:01you can probably find in the description assuming I don't forget to put it there.
130. 8:05Also the company that is helping me make these videos is called Several Nines They are the
131. 8:09ones that have made some of this database clustering software and they decided that
132. 8:13they wanted to help support my channel.
133. 8:15So that is really great for me and it's also great for you because I can make more content.
134. 8:19So if you appreciate these videos, go check out their stuff (obviously we are going to
135. 8:24check it out because we are going to be using their stuff throughout this series) but, I
136. 8:26encourage you to go to them and say "Hey!
137. 8:30I saw you from CalebTheVideoMaker2 you should pay him tons of money!"
138. 8:35You know that would help me out.
139. 8:37So yeah guys!
140. 8:39That's all I have.
141. 8:40Please please please remember to subscribe to this channel because there is going to
142. 8:43be lot of great new content coming out and I'm also going to go back and finish my C
143. 8:47Programming series...
144. 8:48I know.... I'll get to it.
145. 8:50Just relax!
146. 8:51So stay tuned.
147. 8:52One last thing check out the newsletter, that will be used to give you guys notifications
148. 8:57of cool new stuff going on with CalebTheVideoMaker2.
149. 9:00Lastly follow me on social networks and all of that good stuff...
150. 9:03Alright that is enough advertising for like a week!
151. 9:06I will see you guys in the next video.
152. 9:08Hopefully this was helpful.
153. 9:09If you have any questions at all please leave them in the description....
154. 9:11[face palm] leave them as a comment and I will see if I can help you out!
155. 9:16Thanks and I will see you in the next one!