1
00:00:00,000 --> 00:00:02,573
‫So let's get our users post table and

2
00:00:02,573 --> 00:00:05,160
‫on it we're going to enable, DynamoDB stream.

3
00:00:05,160 --> 00:00:07,533
‫So to do so let's go to exports and streams,

4
00:00:07,533 --> 00:00:11,171
‫and here we're going to have DynamoDB stream details,

5
00:00:11,171 --> 00:00:12,567
‫and we're going to enable it.

6
00:00:12,567 --> 00:00:14,560
‫Now we have the option to choose

7
00:00:14,560 --> 00:00:16,520
‫which type of view we want to have

8
00:00:16,520 --> 00:00:18,370
‫within our DynamoDB stream.

9
00:00:18,370 --> 00:00:19,853
‫And it can be key attributes, new image,

10
00:00:19,853 --> 00:00:22,051
‫all image or new and old images.

11
00:00:22,051 --> 00:00:24,760
‫So I'm going to keep the last option

12
00:00:24,760 --> 00:00:26,519
‫to get as much information as possible,

13
00:00:26,519 --> 00:00:28,291
‫and I will enable this stream.

14
00:00:28,291 --> 00:00:29,320
‫Okay, great.

15
00:00:29,320 --> 00:00:31,213
‫So now my stream is enabled and within it,

16
00:00:31,213 --> 00:00:32,888
‫as you can see, if I scroll down,

17
00:00:32,888 --> 00:00:34,040
‫there is the trigger.

18
00:00:34,040 --> 00:00:36,568
‫And the trigger, is what is this stream

19
00:00:36,568 --> 00:00:37,500
‫going to trigger?

20
00:00:37,500 --> 00:00:38,755
‫So we can create a trigger.

21
00:00:38,755 --> 00:00:42,200
‫And here we have a Lambda function that can be invoked

22
00:00:42,200 --> 00:00:45,133
‫every time your DynamoDB stream is updated.

23
00:00:45,133 --> 00:00:46,830
‫So to do so, well, let's go ahead

24
00:00:46,830 --> 00:00:48,461
‫and create a new function.

25
00:00:48,461 --> 00:00:49,294
‫Okay.

26
00:00:49,294 --> 00:00:51,360
‫And we can use a blueprint.

27
00:00:51,360 --> 00:00:54,250
‫And in here I can type DynamoDB,

28
00:00:54,250 --> 00:00:57,900
‫and we have DynamoDB process stream Python.

29
00:00:57,900 --> 00:00:59,670
‫Which is going to log all the updates

30
00:00:59,670 --> 00:01:00,503
‫made to a table.

31
00:01:00,503 --> 00:01:01,336
‫So this is good.

32
00:01:01,336 --> 00:01:02,810
‫Let's configure it

33
00:01:02,810 --> 00:01:06,878
‫and I'll call it Lambda demo, DynamoDB stream.

34
00:01:06,878 --> 00:01:09,770
‫Next, we're going to create a new role

35
00:01:09,770 --> 00:01:11,110
‫with basic Lambda permissions,

36
00:01:11,110 --> 00:01:12,610
‫and we'll make sure to edit this role,

37
00:01:12,610 --> 00:01:14,912
‫to add the permissions, to read from DynamoDB.

38
00:01:14,912 --> 00:01:16,900
‫Now for the DynamoDB triggers,

39
00:01:16,900 --> 00:01:18,700
‫we need to create the trigger.

40
00:01:18,700 --> 00:01:21,111
‫So is going to be the users post,

41
00:01:21,111 --> 00:01:22,145
‫which table was it?

42
00:01:22,145 --> 00:01:23,590
‫The users post table?

43
00:01:23,590 --> 00:01:24,880
‫Yes, indeed.

44
00:01:24,880 --> 00:01:26,950
‫And the batch size is 100.

45
00:01:26,950 --> 00:01:27,783
‫Okay.

46
00:01:27,783 --> 00:01:29,040
‫So this is how many records will read at a time.

47
00:01:29,040 --> 00:01:30,260
‫The batch window, if you wanted to

48
00:01:30,260 --> 00:01:32,280
‫gather records before invoking the functions,

49
00:01:32,280 --> 00:01:33,534
‫so to be more efficient.

50
00:01:33,534 --> 00:01:35,040
‫And the starting position.

51
00:01:35,040 --> 00:01:36,410
‫So do you want to read from the start or

52
00:01:36,410 --> 00:01:38,001
‫from the end of the stream, just in case

53
00:01:38,001 --> 00:01:40,640
‫the stream had been already created.

54
00:01:40,640 --> 00:01:41,640
‫So we're good.

55
00:01:41,640 --> 00:01:42,473
‫We enable the trigger.

56
00:01:42,473 --> 00:01:43,306
‫And as you can see, what it does is

57
00:01:43,306 --> 00:01:45,100
‫that it just prints the records

58
00:01:45,100 --> 00:01:46,247
‫that we get out of the stream,

59
00:01:46,247 --> 00:01:48,090
‫into the logs we'll be able to

60
00:01:48,090 --> 00:01:50,143
‫view this in CloudWatch logs.

61
00:01:52,596 --> 00:01:54,540
‫So now we have created the function,

62
00:01:54,540 --> 00:01:55,730
‫but we get an error, which is that

63
00:01:55,730 --> 00:01:57,705
‫the record or the function can not access

64
00:01:57,705 --> 00:02:01,053
‫our stream because we have missing IAM information.

65
00:02:01,053 --> 00:02:02,430
‫So we're going to fix this.

66
00:02:02,430 --> 00:02:03,795
‫So we click on our function

67
00:02:03,795 --> 00:02:05,630
‫and then under configuration,

68
00:02:05,630 --> 00:02:06,909
‫we're going to go under permissions,

69
00:02:06,909 --> 00:02:08,905
‫and this is the execution role.

70
00:02:08,905 --> 00:02:11,700
‫Now we have to click on this execution role

71
00:02:11,700 --> 00:02:13,980
‫and we're going to add the necessary permissions

72
00:02:13,980 --> 00:02:15,113
‫to read from DynamoDB.

73
00:02:15,113 --> 00:02:16,978
‫So we'll attach a policy

74
00:02:16,978 --> 00:02:19,305
‫and I will look for DynamoDB,

75
00:02:19,305 --> 00:02:22,387
‫and we'll have DynamoDB read only access

76
00:02:22,387 --> 00:02:24,090
‫because what we're doing is that we're

77
00:02:24,090 --> 00:02:26,189
‫actually reading from DynamoDB.

78
00:02:26,189 --> 00:02:28,310
‫So this is good.

79
00:02:28,310 --> 00:02:29,830
‫And this one

80
00:02:31,870 --> 00:02:34,070
‫is also good to read from DynamoDB.

81
00:02:34,070 --> 00:02:35,324
‫So we'll attach these two just in case,

82
00:02:35,324 --> 00:02:37,370
‫but this has meant for Lambda.

83
00:02:37,370 --> 00:02:38,332
‫So probably a little bit better.

84
00:02:38,332 --> 00:02:39,847
‫So let's attach this policy

85
00:02:39,847 --> 00:02:42,630
‫and to be honest, one of these is going to work.

86
00:02:42,630 --> 00:02:44,070
‫I'm trying to make this as simple as possible,

87
00:02:44,070 --> 00:02:45,778
‫which is why I'm not spending a lot of time on this.

88
00:02:45,778 --> 00:02:47,751
‫So let's refresh now this page,

89
00:02:47,751 --> 00:02:50,570
‫and it seems like we're good to go.

90
00:02:50,570 --> 00:02:53,174
‫So we have more actions on DynamoDB.

91
00:02:53,174 --> 00:02:54,300
‫So this is good.

92
00:02:54,300 --> 00:02:55,460
‫Okay.

93
00:02:55,460 --> 00:02:57,322
‫And now if we refresh this,

94
00:02:57,322 --> 00:02:59,071
‫we can choose this function

95
00:02:59,071 --> 00:03:01,117
‫and set the batch size in 100

96
00:03:01,117 --> 00:03:02,517
‫and we create this trigger.

97
00:03:02,517 --> 00:03:04,959
‫So now that means that my DynamoDB stream

98
00:03:04,959 --> 00:03:07,625
‫is going to trigger my Lambda function.

99
00:03:07,625 --> 00:03:10,047
‫And if I go back into my Lambda function

100
00:03:10,047 --> 00:03:11,643
‫and refresh this page,

101
00:03:12,590 --> 00:03:14,260
‫we can see the DynamoDB

102
00:03:14,260 --> 00:03:16,590
‫is indeed triggering my Lambda function.

103
00:03:16,590 --> 00:03:18,293
‫So this is an enabled type of integration

104
00:03:18,293 --> 00:03:20,063
‫with these settings.

105
00:03:20,063 --> 00:03:21,500
‫Okay, good.

106
00:03:21,500 --> 00:03:23,390
‫So next, what I'm going to do is just test it out.

107
00:03:23,390 --> 00:03:25,717
‫So we're going to go to our table

108
00:03:25,717 --> 00:03:28,298
‫and what I'm going to do is click on view items.

109
00:03:28,298 --> 00:03:30,165
‫And we're going to do a few things.

110
00:03:30,165 --> 00:03:32,309
‫For example, let's take this item,

111
00:03:32,309 --> 00:03:34,826
‫the second post of John, we're going to action,

112
00:03:34,826 --> 00:03:37,279
‫edit it, and then I'm going to modify.

113
00:03:37,279 --> 00:03:39,933
‫So I'm going to say a second post 'yay' edit.

114
00:03:40,990 --> 00:03:42,730
‫And click on save change.

115
00:03:42,730 --> 00:03:43,870
‫So this is good.

116
00:03:43,870 --> 00:03:45,732
‫And then we'll take Alice

117
00:03:45,732 --> 00:03:47,670
‫and we're going to do action

118
00:03:47,670 --> 00:03:48,800
‫and then duplicate.

119
00:03:48,800 --> 00:03:50,280
‫So it's going to create a new thing

120
00:03:50,280 --> 00:03:53,360
‫and I'm going to just add a bit more data

121
00:03:53,360 --> 00:03:56,149
‫as a new Alice blog

122
00:03:56,149 --> 00:03:57,983
‫and then create item.

123
00:03:59,890 --> 00:04:01,520
‫And then finally, we actually don't like this blog,

124
00:04:01,520 --> 00:04:03,480
‫so I'm going to delete it.

125
00:04:03,480 --> 00:04:07,460
‫So I'm going to do action and then delete items.

126
00:04:07,460 --> 00:04:08,830
‫And yes.

127
00:04:08,830 --> 00:04:09,663
‫Okay.

128
00:04:09,663 --> 00:04:10,840
‫So we've done three kinds of operations.

129
00:04:10,840 --> 00:04:12,974
‫We've had an update, a create and a delete.

130
00:04:12,974 --> 00:04:14,887
‫And so we went to do my Lambda function.

131
00:04:14,887 --> 00:04:17,550
‫My Lambda function executed this code,

132
00:04:17,550 --> 00:04:19,756
‫which was printing, so logging these events.

133
00:04:19,756 --> 00:04:22,180
‫And so what I need you to do is just go into

134
00:04:22,180 --> 00:04:25,540
‫CloudWatch logs and have a look at whether

135
00:04:25,540 --> 00:04:27,278
‫or not we saw these informational logs

136
00:04:27,278 --> 00:04:30,173
‫So let's click on view the logs in CloudWatch logs.

137
00:04:31,418 --> 00:04:35,027
‫And here we have some information around this log stream.

138
00:04:35,027 --> 00:04:36,970
‫And as you can see in this log stream

139
00:04:36,970 --> 00:04:38,169
‫you get a lot of information.

140
00:04:38,169 --> 00:04:39,710
‫Okay, so we get one line.

141
00:04:39,710 --> 00:04:41,005
‫So this was a modify

142
00:04:41,005 --> 00:04:43,160
‫and this was the DynamoDB records.

143
00:04:43,160 --> 00:04:45,400
‫So it gives you the key, the user ID,

144
00:04:45,400 --> 00:04:46,786
‫and as well as the new image.

145
00:04:46,786 --> 00:04:47,750
‫Okay.

146
00:04:47,750 --> 00:04:48,583
‫And the content,

147
00:04:48,583 --> 00:04:51,178
‫so we can see yes, a second post 'yay' edit.

148
00:04:51,178 --> 00:04:53,120
‫And we can also see the old image

149
00:04:53,120 --> 00:04:54,620
‫of what it was before.

150
00:04:54,620 --> 00:04:56,311
‫So that was like for one request,

151
00:04:56,311 --> 00:04:57,975
‫then we have an insert.

152
00:04:57,975 --> 00:05:00,386
‫And so again, we can see, the DynamoDB record in it.

153
00:05:00,386 --> 00:05:03,450
‫And then the new image and the, there is

154
00:05:03,450 --> 00:05:05,390
‫no old image because obviously we wasn't inserts.

155
00:05:05,390 --> 00:05:06,434
‫So there was nothing before.

156
00:05:06,434 --> 00:05:07,723
‫And then we get a remove.

157
00:05:07,723 --> 00:05:10,274
‫And again, this remove operation was logged.

158
00:05:10,274 --> 00:05:12,210
‫We have the old image, and obviously there

159
00:05:12,210 --> 00:05:14,270
‫is no new image because the thing was removed.

160
00:05:14,270 --> 00:05:15,103
‫Okay.

161
00:05:15,103 --> 00:05:16,119
‫So that's fairly easy.

162
00:05:16,119 --> 00:05:17,516
‫We just enable the stream

163
00:05:17,516 --> 00:05:19,130
‫and you went to Lambda function

164
00:05:19,130 --> 00:05:20,380
‫and the Lambda function was logging it,

165
00:05:20,380 --> 00:05:22,882
‫but this is the basis to have these

166
00:05:22,882 --> 00:05:25,260
‫kinds of integrations with DynamoDB streams.

167
00:05:25,260 --> 00:05:26,093
‫Okay.

168
00:05:26,093 --> 00:05:28,090
‫Lastly, please make sure to disable the trigger.

169
00:05:28,090 --> 00:05:30,340
‫So on the DynamoDB, you take this trigger

170
00:05:30,340 --> 00:05:32,205
‫and you disabled it or delete it,

171
00:05:32,205 --> 00:05:34,285
‫whatever you want, and you'll be good to go.

172
00:05:34,285 --> 00:05:36,260
‫So that's it for this lecture.

173
00:05:36,260 --> 00:05:37,093
‫I hope you liked it.

174
00:05:37,093 --> 00:05:39,010
‫And I will see you in the next lecture.