1
00:00:00,270 --> 00:00:00,780
‫So

2
00:00:03,630 --> 00:00:05,230
‫we're going to go fast.

3
00:00:05,240 --> 00:00:05,640
‫All right.

4
00:00:09,280 --> 00:00:11,970
‫Then we're going to end the show because we're past our hour.

5
00:00:11,970 --> 00:00:15,240
‫I want to get you guys some feedback.

6
00:00:15,240 --> 00:00:15,480
‫All right.

7
00:00:15,810 --> 00:00:17,860
‫The first one up is Jacob.

8
00:00:18,030 --> 00:00:23,480
‫There's a whole lot of documentation here. I love documentation Dockerfiles by the way.

9
00:00:23,580 --> 00:00:25,620
‫It's totally fine to put as much as you want.

10
00:00:25,620 --> 00:00:30,420
‫This is actually a YAML file so now we're talking about Compose. Documentation in Dockerfiles or

11
00:00:30,420 --> 00:00:31,980
‫Compose files. Either way.

12
00:00:31,980 --> 00:00:34,550
‫Always a good thing.

13
00:00:34,680 --> 00:00:34,920
‫All right.

14
00:00:34,920 --> 00:00:39,530
‫So he's using a version 3.0 7 which means it's probably for Swarm or something in production like

15
00:00:39,530 --> 00:00:43,680
‫Kubernetes using the Compose on Kubernetes feature set.

16
00:00:43,800 --> 00:00:53,150
‫He's using the official Elastic images from the Elastic there.

17
00:00:54,780 --> 00:00:56,880
‫Let's see you've got your healthcheck.

18
00:00:56,880 --> 00:00:57,690
‫Fantastic.

19
00:00:57,690 --> 00:01:00,140
‫You've got healthchecks. That's great. You've got configs.

20
00:01:00,210 --> 00:01:01,220
‫That's great.

21
00:01:01,290 --> 00:01:05,610
‫You're setting it on a specific network and you're doing host mode on the port

22
00:01:05,640 --> 00:01:12,930
‫so you're giving this direct access to the NIC instead of going through the overlay networks and the

23
00:01:13,560 --> 00:01:14,220
‫routing mesh.

24
00:01:14,220 --> 00:01:15,300
‫That's good.

25
00:01:15,300 --> 00:01:17,420
‫Then, let's see.

26
00:01:20,020 --> 00:01:21,420
‫We've got to deploy down here.

27
00:01:21,420 --> 00:01:24,750
‫Oh, and you're doing endpoint mode DNS round robin.

28
00:01:24,750 --> 00:01:26,310
‫Kudos to you.

29
00:01:26,310 --> 00:01:29,320
‫This is something that a lot of people don't realize.

30
00:01:29,490 --> 00:01:37,200
‫Whenever you're running something in Swarm and you want to disable the virtual IP that sits in front

31
00:01:37,200 --> 00:01:44,190
‫of every overlay service, you want to do that for databases where you only have one node, right, which

32
00:01:44,190 --> 00:01:48,660
‫is a lot of times even if you're doing a mirror of a database you're usually running each one of those

33
00:01:48,660 --> 00:01:49,820
‫in their own service.

34
00:01:49,890 --> 00:01:56,760
‫So there's one instance in a service and that that task of that instance of a container, you don't

35
00:01:56,760 --> 00:02:01,140
‫usually want that virtual IP in front of it because it's now an extra hop. It's another NAT translation.

36
00:02:01,340 --> 00:02:03,250
‫It's more potential problems.

37
00:02:03,270 --> 00:02:10,230
‫If you set endpoint mode to DNS round robin here, that effectively turns off the VIP and has direct

38
00:02:10,230 --> 00:02:11,460
‫access to that container.

39
00:02:11,460 --> 00:02:12,820
‫Kudos to you.

40
00:02:12,900 --> 00:02:18,300
‫I don't see that very often because people don't catch that one. You're also using replicas

41
00:02:18,300 --> 00:02:18,820
‫too.

42
00:02:19,320 --> 00:02:25,090
‫Resource limits of 4G for a gig that's great.

43
00:02:25,140 --> 00:02:31,350
‫Always I recommend always setting resource limits and reservations if you can because that's going to

44
00:02:31,350 --> 00:02:34,920
‫help things all get along inside your cluster.

45
00:02:35,040 --> 00:02:35,330
‫Yeah.

46
00:02:35,340 --> 00:02:38,820
‫Looks like it's running on Docker Swarm. Sweet.

47
00:02:40,910 --> 00:02:42,120
‫Coordination

48
00:02:44,090 --> 00:02:45,110
‫Master.

49
00:02:48,080 --> 00:02:48,420
‫All right.

50
00:02:48,420 --> 00:02:50,220
‫More of the same.

51
00:02:50,490 --> 00:02:51,030
‫More of the same.

52
00:02:51,030 --> 00:02:52,210
‫Good stuff. Good stuff.

53
00:02:52,350 --> 00:02:58,810
‫You're bind mounting a volume. You're not bind mounting. You're using a named volume.

54
00:02:59,170 --> 00:03:05,170
‫You've got placement constraints here so you're putting this on a node that is hard coded to a specific

55
00:03:05,170 --> 00:03:08,950
‫name. You know you want this one to run on that node only.

56
00:03:09,040 --> 00:03:15,130
‫Of course, the weakness here is that if that node goes down, it won't be able to place it anywhere

57
00:03:15,130 --> 00:03:15,390
‫else.

58
00:03:15,400 --> 00:03:20,040
‫Hopefully you've taken that into consideration.

59
00:03:20,260 --> 00:03:20,950
‫All right.

60
00:03:20,950 --> 00:03:22,840
‫Master2, so that's how you're doing this.

61
00:03:22,840 --> 00:03:29,110
‫It looks like you have master1, master2 hard coded in as separate services and master3. A

62
00:03:29,110 --> 00:03:34,750
‫lot of people have to do it this way that when you have a multi-node database cluster, it's usually easier

63
00:03:34,990 --> 00:03:37,290
‫to put each one of these as their own service.

64
00:03:37,300 --> 00:03:42,550
‫So you've done that. It would be nice if we could just make one service with three replicas.

65
00:03:42,550 --> 00:03:50,530
‫You can find that with some examples using the autopilot pattern. If you look up autopilot pattern IO,

66
00:03:50,860 --> 00:03:56,650
‫or if you just Google your database technology with the word autopilot, sometimes you can find configurations

67
00:03:56,650 --> 00:04:00,270
‫and automation scripts that will help you do it all in one service.

68
00:04:00,340 --> 00:04:02,360
‫There's pros and cons to each.

69
00:04:02,380 --> 00:04:05,080
‫I personally tend to just do it the way you're doing it.

70
00:04:05,680 --> 00:04:10,180
‫I feel like it's simpler even though it's more YAML and it's a little bit more verbose.

71
00:04:10,180 --> 00:04:11,490
‫One thing you could do here.

72
00:04:11,620 --> 00:04:16,710
‫One huge improvement is if these are all all the same parts here.

73
00:04:16,710 --> 00:04:17,080
‫Right.

74
00:04:17,080 --> 00:04:23,710
‫All the same stuff, you can template that, shorten this file significantly by only putting that in a template

75
00:04:23,710 --> 00:04:24,400
‫block.

76
00:04:24,580 --> 00:04:29,490
‫I talk more about that in this...

77
00:04:29,740 --> 00:04:33,450
‫This right here, Jacob. I'll put this in chat.

78
00:04:33,490 --> 00:04:38,610
‫This is three different advanced Docker Compose features that a lot people don't use.

79
00:04:38,710 --> 00:04:42,310
‫One of them is on templating.

80
00:04:42,370 --> 00:04:49,490
‫So if you see the example here, you can you can throw the templating right there.

81
00:04:49,810 --> 00:04:52,530
‫Basically what you're saying is this is what I want in the template

82
00:04:52,540 --> 00:04:57,810
‫and this is where I want you to put it, over and over in each image, or in each service rather.

83
00:04:57,850 --> 00:05:02,290
‫So, a lot of that boilerplate stuff, like you could template the whole thing or you could just template

84
00:05:02,290 --> 00:05:06,550
‫parts of them and have multiple templates, and Docker has documentation on that.

85
00:05:06,550 --> 00:05:10,890
‫That would help make your file smaller and we call it dry.

86
00:05:10,900 --> 00:05:11,170
‫Right.

87
00:05:11,170 --> 00:05:16,030
‫Doing things once. Don't repeat yourself.

88
00:05:16,030 --> 00:05:16,950
‫D R Y

89
00:05:17,180 --> 00:05:18,710
‫You could do that.

90
00:05:18,710 --> 00:05:22,730
‫That would help you alleviate a lot of this repetitive stuff especially around the healthchecks

91
00:05:23,150 --> 00:05:25,940
‫and the deployment stuff.

92
00:05:25,940 --> 00:05:30,740
‫Then you've got your data nodes. Everything's looking good there. You're using your healthchecks. You've

93
00:05:30,740 --> 00:05:42,250
‫got your network set. Your volumes. Let me go down past some of this. You're hard coding stuff to each

94
00:05:42,250 --> 00:05:44,800
‫node. I really wish

95
00:05:49,140 --> 00:05:53,220
‫that we had a way to tell it don't run...like here's a placement constraint.

96
00:05:53,220 --> 00:05:54,920
‫Don't run it on one

97
00:05:55,020 --> 00:05:57,270
‫that is where the other ones run.

98
00:05:57,300 --> 00:06:02,730
‫There's some hope for you. There's two things you can do here. You can look at placement preferences.

99
00:06:03,180 --> 00:06:08,340
‫If you have your different nodes in availability zones and you simply want your database to make

100
00:06:08,340 --> 00:06:15,270
‫sure that it has one copy in each availability zone, like an AWS or something, then you can add labels

101
00:06:15,270 --> 00:06:23,910
‫to each node. Then you just go in here and say I would prefer you to spread these out over my label.

102
00:06:23,940 --> 00:06:28,770
‫You just give it a label and a placement preference instead of a constraint, will allow it to put

103
00:06:28,770 --> 00:06:33,220
‫those on the different servers in the different zones.

104
00:06:33,270 --> 00:06:40,080
‫But the cool thing here is if one zone, or one server, goes down, it will still be able to reassign that

105
00:06:40,080 --> 00:06:41,490
‫somewhere else.

106
00:06:41,490 --> 00:06:47,520
‫Now the worst case here is that two of these are running on the same server but that's probably not

107
00:06:47,520 --> 00:06:53,220
‫so bad if you're able to...I mean one thing might be the data getting the data from one zone over the

108
00:06:53,220 --> 00:06:56,080
‫other. Once you've solved some of those problems.

109
00:06:56,110 --> 00:06:56,940
‫Yeah.

110
00:06:57,030 --> 00:07:01,050
‫Yeah. You're saying, so I can use constraint and allowed to lose one of the physical nodes.

111
00:07:01,050 --> 00:07:01,260
‫Yeah.

112
00:07:01,290 --> 00:07:07,050
‫The thing here is you're you're making it a little bit more brittle by assigning it to Node host

113
00:07:07,050 --> 00:07:11,760
‫names. You have to those specific hosts up. Ideally, like if you're in AWS or something

114
00:07:11,760 --> 00:07:14,460
‫where you can have your servers auto create.

115
00:07:14,460 --> 00:07:17,340
‫So, if a server dies it all creates a new one.

116
00:07:17,840 --> 00:07:18,150
‫Yeah.

117
00:07:18,180 --> 00:07:22,680
‫If you've accounted for all that, great. There's nothing wrong with placement constraints in this way.

118
00:07:22,680 --> 00:07:26,490
‫It just means that those nodes have to be there or those containers die.

119
00:07:26,490 --> 00:07:33,030
‫The other thing is there is a new feature coming in 19.03 and the way you learn about these new features

120
00:07:33,450 --> 00:07:43,950
‫is if you go to Docker on github and you go to Docker-ce releases. I will post this in chat and you

121
00:07:43,950 --> 00:07:48,510
‫can look up new Swarm features. There is a new Swarm feature version that will allow you

122
00:07:48,510 --> 00:07:56,130
‫to run replicas but tell it never run more than X of these replicas on the same node. Super cool feature

123
00:07:56,160 --> 00:08:01,590
‫and helps people ensure that their databases don't all get assigned the same node. You might want

124
00:08:01,590 --> 00:08:07,020
‫to check that out as a more flexible way to ensure they're not on the same note.

125
00:08:07,980 --> 00:08:12,910
‫I think if I scroll down down to Swarm.

126
00:08:13,510 --> 00:08:20,320
‫Yeah. Added support for maximum replicas per node. That's a new feature in the forthcoming 19.03 release

127
00:08:20,320 --> 00:08:25,750
‫that's already in prerelease now so we should be seeing this within the next few weeks or months.

128
00:08:25,750 --> 00:08:26,560
‫You can check that out.

129
00:08:26,560 --> 00:08:29,490
‫That might help you with the constraints.

130
00:08:29,600 --> 00:08:30,170
‫All right.

131
00:08:30,360 --> 00:08:31,590
‫I want to move ahead a little bit.

132
00:08:31,590 --> 00:08:34,610
‫Sorry I can't review all this. I'm moving it down at the bottom.

133
00:08:34,650 --> 00:08:40,430
‫You got your networks, attachable true and proxy.

134
00:08:40,770 --> 00:08:41,940
‫All looks good there.

135
00:08:41,940 --> 00:08:48,150
‫You got volume so you're using the default volume driver so that that way that means that all of this

136
00:08:48,150 --> 00:08:50,220
‫data is stuck on the node that it's on.

137
00:08:50,910 --> 00:08:57,120
‫If you have any shared storage, you might consider REX-Ray or another volume driver so that you can get

138
00:08:57,120 --> 00:09:01,680
‫that storage off that disk. That way, when one of the nodes fails and it wants to create that somewhere

139
00:09:01,680 --> 00:09:04,950
‫else, it will reattach that database volume

140
00:09:04,950 --> 00:09:05,850
‫on the other node.

141
00:09:05,920 --> 00:09:06,390
‫All right.

142
00:09:06,480 --> 00:09:14,800
‫You may have already looked at that. You've got traefik certificates. I could talk about that for

143
00:09:14,800 --> 00:09:19,720
‫a while but we're going to run out of time. I'll leave the traffic certificate stuff for another

144
00:09:19,720 --> 00:09:23,970
‫day. Then you've got configs and other files.

145
00:09:23,980 --> 00:09:27,750
‫This is great. Using all the configs.

146
00:09:29,340 --> 00:09:30,390
‫As you should.

147
00:09:30,390 --> 00:09:34,800
‫I don't see Secrets in here. I'm assuming at some point you're doing to need Secrets and you might need

148
00:09:34,800 --> 00:09:42,780
‫to store those in Secret somewhere. Other than that great YAML. Definitely one of the better ones I've

149
00:09:42,780 --> 00:09:43,200
‫seen.

150
00:09:43,200 --> 00:09:45,750
‫I think there's very little to do here.

151
00:09:45,750 --> 00:09:51,300
‫I think in terms of making it sort of using all the perfect features. The templating is a thing. Considering

152
00:09:51,300 --> 00:09:56,580
‫different volume drivers and considering the new feature. If not placement preferences, the new feature

153
00:09:56,580 --> 00:10:19,110
‫for max replicas per node.

154
00:10:19,120 --> 00:10:20,620
‫Thanks for watching.

155
00:10:20,620 --> 00:10:26,050
‫You can click SUBSCRIBE AND the notification bell to get an alert when I go live so you can join and

156
00:10:26,050 --> 00:10:28,110
‫ask your Devops and Docker questions.

157
00:10:28,150 --> 00:10:32,980
‫You can watch some of my other videos over there and you can do what I'm about to do and just go take

158
00:10:32,980 --> 00:10:33,460
‫a nap.