1

00:00:01,880 --> 00:00:02,330

So in this session



2

00:00:02,380 --> 00:00:08,500

we are going to learn about setting up a Master Slave Configuration, which is going



3

00:00:08,500 --> 00:00:15,460

to be a Production like setup and also we will try to simulate a Production Failure.



4

00:00:15,460 --> 00:00:22,090

So we are going to shut down one Master Server and then we will be creating a New Master Server on the



5

00:00:22,090 --> 00:00:26,890

fly and the existing Slave Server, we are going to point to the New Master Server



6

00:00:30,880 --> 00:00:39,400

and in this example I'm going to use three servers. So first server is 10.128.0.4 and



7

00:00:39,400 --> 00:00:46,760

Host name is itpanther02 and Second Server is going to be a Slave Server, which is having IP address



8

00:00:46,760 --> 00:00:52,880

of 10.128.0.5 and



9

00:00:52,910 --> 00:00:56,130

Host name is itpanther03.  Okay.



10

00:00:56,150 --> 00:01:02,420

So we will set up a Master Slave Configuration on these two servers and then we are going to shut down



11

00:01:02,960 --> 00:01:11,610

a Master Server, which is 10.128.0.4 and then we are going to log into a New Server



12

00:01:11,640 --> 00:01:19,740

which is, 10.128.0.6 and there are we are going to set up Redis again. A brand new installation



13

00:01:20,910 --> 00:01:28,110

and then we are going to, you know, move these existing server or point this existing server, Slave Server



14

00:01:28,110 --> 00:01:30,490

to this New Master Server.



15

00:01:30,780 --> 00:01:37,610

And of course we'll be making sure that whatever data which has been written on, you know, previously Master



16

00:01:37,630 --> 00:01:40,740

and Slave, that should be available in the New Master Server.



17

00:01:41,340 --> 00:01:41,610

Okay.



18

00:01:41,610 --> 00:01:48,050

So basically we should be having 0 Data Loss. So let's begin.



19

00:01:54,230 --> 00:01:59,840

So you can verify this is a first server, which is going to be a Master Server. The IP address is



20

00:02:00,050 --> 00:02:01,190

10.128.0.4



21

00:02:04,080 --> 00:02:04,820

Right now,



22

00:02:05,580 --> 00:02:15,630

I am in /home/redisadmin directory and I have downloaded the software which is Redis 5



23

00:02:15,780 --> 00:02:22,030

And also I have extracted this software and now we have a Redis-stable directory.



24

00:02:22,740 --> 00:02:24,810

So let's go into this directory



25

00:02:32,360 --> 00:02:37,230

and let's make changes into Redis.conf,  Configuration File.



26

00:02:44,370 --> 00:02:49,850

So the first thing which we need to do, is change the bind address to the actual IP address, where we



27

00:02:49,860 --> 00:02:54,050

are running this Redis Server.



28

00:02:54,150 --> 00:02:58,410

So it is going to be in this case 10.128.0.4



29

00:03:06,500 --> 00:03:08,670

and if  you want to change the port, you can change it.



30

00:03:08,690 --> 00:03:12,560

In my case,  I'm just going to leave it to default which is 6 3 7 9



31

00:03:17,810 --> 00:03:23,780

and log file I'm going to change it to /tmp/redis.log



32

00:03:24,080 --> 00:03:24,340

OK.



33

00:03:24,350 --> 00:03:30,310

So we want logs to be written to /tmp/redis.log



34

00:03:40,040 --> 00:03:43,700

and also we want RDB back up to be created to



35

00:03:46,350 --> 00:03:51,300

Directory which is called,  /home/redisadmin



36

00:03:54,040 --> 00:03:54,320

OK.



37

00:03:54,330 --> 00:04:01,650

So you see, db file name is set up to dump.rdb  and if you want, you can change this name as well.



38

00:04:02,370 --> 00:04:08,850

So in this example I'm not going to change it. I'm going to leave it as it is  and directory is going to



39

00:04:08,850 --> 00:04:10,650

be /home/redisadmin



40

00:04:14,040 --> 00:04:22,830

So the RDB back up will be creating into this directory. So that's all required on the Master Configuration.



41

00:04:22,850 --> 00:04:24,440

Now I'm going to save and exit



42

00:04:31,290 --> 00:04:31,720

okay.



43

00:04:31,750 --> 00:04:34,810

Now let's log into SlaveS erver.



44

00:04:39,310 --> 00:04:45,700

So either you can open a new session, new and log In there or otherwise you can just use ssh to log



45

00:04:45,700 --> 00:04:53,510

into any other sever and in my case I have set up  Passwordless authentication .



46

00:04:53,850 --> 00:04:59,820

So basically I'll set up a ssh key authentication.  So I don't need to provide password.



47

00:05:00,020 --> 00:05:00,350

OK.



48

00:05:00,360 --> 00:05:08,090

In your case if you are getting some error related to authentication,  just make sure you have setup ssh



49

00:05:08,100 --> 00:05:15,940

authentication or otherwise you can open a New Session and there you can provide the IP details of



50

00:05:15,940 --> 00:05:25,580

Slave Server.  So I'm going to now log into  itpanther03, which is having IP address of



51

00:05:25,590 --> 00:05:26,760

10.128.0.5



52

00:05:30,130 --> 00:05:35,510

Okay now we can verify the IP address by using Host name space -i



53

00:05:35,510 --> 00:05:40,280

Command and you can see the IP address is 10.128.0.5



54

00:05:41,360 --> 00:05:44,970

And currently we are in to /home/redisadmin directory



55

00:05:45,020 --> 00:05:53,630

And if I do ls-lrt,  you can see currently we do not have Redis software available here.



56

00:05:55,780 --> 00:06:01,420

So what I will do is since I already have the Software on itpanther02 server. So I'm going



57

00:06:01,420 --> 00:06:02,790

to copy from there.



58

00:06:03,710 --> 00:06:09,460

So I'll exit from here and we are back to itpanther02 server.



59

00:06:09,480 --> 00:06:10,870

So here we have the software.



60

00:06:10,870 --> 00:06:16,290

So I will use scp  command to copy the software to the Remote Server.



61

00:06:19,350 --> 00:06:24,900

So command to do that is scp  -r  Redis-stable.



62

00:06:24,900 --> 00:06:29,440

I want to copy this Complete Directory and sub- directories.



63

00:06:29,700 --> 00:06:32,780

And now we need to provide the Remote Server where you want to copy this.



64

00:06:32,780 --> 00:06:35,880

So it is going to be itpanther03



65

00:06:36,060 --> 00:06:39,340

So I'm providing the Host name but you can do the same with IP name as well.



66

00:06:40,740 --> 00:06:43,130

And we want to copy to the Home Directory.



67

00:06:43,230 --> 00:06:51,000

So the way to do that is, you need to provide : after Host name and then you use ~ character



68

00:06:51,660 --> 00:06:59,780

and then /. Hit enter. and Software copy is in progress.



69

00:07:03,170 --> 00:07:03,470

okay.



70

00:07:03,480 --> 00:07:10,620

Let me clear the screen and let me go to itpanther03 server.



71

00:07:10,690 --> 00:07:14,730

We verify Host name  -i



72

00:07:15,340 --> 00:07:16,400

We verify the IP.



73

00:07:16,400 --> 00:07:24,370

Now we can do ls-lrt. We can see Redis-stable is already  moved here.



74

00:07:28,180 --> 00:07:33,040

Now I'm going to make the configuration changes here. Okay.



75

00:07:33,220 --> 00:07:37,840

So by default whatever configuration which we had done their on Master,  has come here because we just



76

00:07:37,840 --> 00:07:42,890

copy pasted the software on this machine.



77

00:07:43,110 --> 00:07:48,150

However in this case we need to make sure we change the bind address because this is a different server.



78

00:07:48,180 --> 00:07:55,990

So we need to provide the IP address of this server, which is in this case going to be



79

00:07:56,010 --> 00:07:57,360

10.128.0.5



80

00:08:02,570 --> 00:08:07,140

and I want all the logs to be going to /tmp/redis.log



81

00:08:07,140 --> 00:08:10,470

So this is already good. I do not want to make any changes here.



82

00:08:13,670 --> 00:08:25,070

And now next thing which we need to change here is related to you know,  the RDB backup.



83

00:08:25,070 --> 00:08:31,250

So I think this is also OK in this case. So we will just leave it to the same directory because I had



84

00:08:31,250 --> 00:08:35,100

the same directory standard followed on all the servers.



85

00:08:35,880 --> 00:08:36,240

OK.



86

00:08:36,260 --> 00:08:37,890

So I'm just going to leave it as it is.



87

00:08:37,910 --> 00:08:47,570

And now we need to set up Replica. So on Master Server we have not made any changes to this line or



88

00:08:47,570 --> 00:08:50,150

this directive. Here we need to make changes.



89

00:08:50,240 --> 00:08:57,860

So uncomment the line and after Replica of,  you need to provide the IP address of the Master Server



90

00:08:57,920 --> 00:09:03,910

which is in this case going to be 10.128.0.4



91

00:09:04,630 --> 00:09:05,030

Okay.



92

00:09:05,030 --> 00:09:09,010

And Master Port, as we know we haven't made any changes  in the port.



93

00:09:09,020 --> 00:09:14,810

So by default it is going to be running on Port 6 3 7 9



94

00:09:17,740 --> 00:09:18,390

So that's.



95

00:09:18,430 --> 00:09:26,470

Now we can save and exit  and now we have software installed on, I mean the configuration is done on both the



96

00:09:26,470 --> 00:09:28,780

server, which is Master Server and the Slave Server.



97

00:09:28,780 --> 00:09:30,080

So now we can go ahead and



98

00:09:33,580 --> 00:09:34,600

start these Servers.



99

00:09:34,600 --> 00:09:34,800

Okay.



100

00:09:34,810 --> 00:09:38,460

So  let me start Master first.



101

00:09:38,740 --> 00:09:42,370

So I will go back to



102

00:09:45,700 --> 00:09:47,740

you know,  Master Server.



103

00:09:47,740 --> 00:09:49,690

We will verify the IP address.



104

00:09:49,960 --> 00:10:02,970

So this is the IP address of Master Server.



105

00:10:03,740 --> 00:10:06,480

So I will go to Redis -stable directory.



106

00:10:06,710 --> 00:10:10,430

And here we need to go inside src directory



107

00:10:20,250 --> 00:10:20,550

okay.



108

00:10:20,560 --> 00:10:23,090

Here you see we have Redis -server utility.



109

00:10:23,090 --> 00:10:25,680

So this is what we need to start.



110

00:10:25,930 --> 00:10:27,380

Let me clear the screen first.



111

00:10:27,400 --> 00:10:36,140

So we are into this directory and now I'm doing /./Redis- Server



112

00:10:37,100 --> 00:10:42,660

And when we are starting Redis,  we also need to provide the full path of the configuration file.



113

00:10:42,740 --> 00:10:43,990

Redis.conf file.



114

00:10:45,320 --> 00:10:57,220

So I know that is located at /home/redisadmin/redis-stable/redis.conf



115

00:10:59,340 --> 00:11:02,520

And also I want to start this as a background process.



116

00:11:02,520 --> 00:11:09,990

So in the end, I'm giving & symbol. So that's it. If we hit enter, now Masters should start



117

00:11:11,700 --> 00:11:15,090

and also we can verify by checking the logs.



118

00:11:15,090 --> 00:11:21,930

So as we remember in the Configuration, we have given the,  that logs should be saved  to



119

00:11:23,850 --> 00:11:24,750

/tmp/redis.log



120

00:11:25,020 --> 00:11:26,190

So let's check the logs.



121

00:11:31,410 --> 00:11:31,810

Okay.



122

00:11:31,830 --> 00:11:36,660

So we see Redis is started. It is  saying Ready to accept connections. So everything looks okay here.



123

00:11:40,230 --> 00:11:41,580

So now I'm going to



124

00:11:44,200 --> 00:11:48,340

move to Slave Server which, is 10.128.0.5



125

00:11:55,980 --> 00:11:56,680

okay.



126

00:11:56,710 --> 00:11:59,530

And you can verify the IP address.



127

00:11:59,530 --> 00:12:01,000

So this is the correct IP address.



128

00:12:01,000 --> 00:12:04,990

Now let's go to Redis table.



129

00:12:04,990 --> 00:12:06,580

Go to cd src



130

00:12:10,860 --> 00:12:19,780

and here we can do Redis-server and also provide the full path of the wherever your configuration



131

00:12:19,780 --> 00:12:20,620

file is.



132

00:12:20,620 --> 00:12:24,010

So in this case it is at



133

00:12:27,330 --> 00:12:31,130

/home/redisadmin/redis-stable/redis.conf



134

00:12:32,880 --> 00:12:34,670

And also I'm going to use &



135

00:12:43,000 --> 00:12:49,930

and let's see the log by going to /tmp/redis.log



136

00:12:49,950 --> 00:12:55,520

So now on the Slave Server,  when we went to redis.log, you can see that it is saying that Master



137

00:12:55,530 --> 00:12:57,960

Replica Sync is successful.



138

00:12:57,960 --> 00:13:04,500

So basically when we started Slave Server it was knowing that it is a Slave Server and it has to



139

00:13:04,500 --> 00:13:05,880

connect to a Master Server.



140

00:13:06,420 --> 00:13:14,330

So it tried connecting connecting to the Master Server and the connection was successful.



141

00:13:14,370 --> 00:13:15,600

So now we will use



142

00:13:18,470 --> 00:13:21,600

redis-cli utility to connect to Master Node.



143

00:13:28,870 --> 00:13:34,900

So just remember using redis-cli,  you can connect to any number of servers.  You just need



144

00:13:34,900 --> 00:13:40,930

to provide the correct IP address to which you want to connect to.



145

00:13:40,930 --> 00:13:45,790

So I do not, if I want to connect to  Master Server.  I do not need to go to the Master Server.



146

00:13:47,470 --> 00:13:48,190

Okay.



147

00:13:48,250 --> 00:13:52,330

I can just stay on this server which is itpanther03,  which is a Slave Server and



148

00:13:52,330 --> 00:13:55,890

I still can connect to any server.



149

00:13:55,900 --> 00:14:04,430

So I will do redis-cli then space -h



150

00:14:04,430 --> 00:14:11,270

Here you need to provide the  Host name.  Either Host name or IP address.  So let's provide IP address in this



151

00:14:11,270 --> 00:14:21,890

case and also if you are running Redis on non default port, which is the port



152

00:14:21,910 --> 00:14:29,020

Other than 6 3 7 9 then also you can provide that port by using -p and whatever the port



153

00:14:29,080 --> 00:14:30,940

you are running Redis on.



154

00:14:30,940 --> 00:14:37,240

So if you are running on a default port which is  6 3 7 9,  then you do not need to provide the Port but



155

00:14:37,240 --> 00:14:41,520

if you still want to be explicit, then you still can provide the port.



156

00:14:42,360 --> 00:14:43,000

OK.



157

00:14:43,150 --> 00:14:49,290

So it is going to work the same way regardless of whether I use -P or not.



158

00:14:49,520 --> 00:14:58,330

I mean whatever, whether I use this port part or not but let's say in case I had changed the port



159

00:14:58,330 --> 00:15:05,440

from 6 3 7 9 to some other port and then I tried to connect to this node without providing the port



160

00:15:05,440 --> 00:15:11,830

information,  then it will try to connect to 6 3 7 9 port and it will eventually say, that it is not able



161

00:15:11,830 --> 00:15:18,380

to connect.  So in those cases you need to provide the port number.



162

00:15:18,380 --> 00:15:23,140

All right so let's connect. Hit enter and we should be able to connect to the Master Node.



163

00:15:23,900 --> 00:15:31,230

Okay so we see we are able to connect to Master Node and let's do dbsize. So dbsize tells us what is



164

00:15:31,230 --> 00:15:38,280

the total number of keys,  which are available right now in Redis. So since it is a Brand New Fresh



165

00:15:38,370 --> 00:15:42,250

Installation, we do not have any data stored.



166

00:15:42,290 --> 00:15:45,060

Okay we can verify the same with keys *.



167

00:15:45,090 --> 00:15:47,500

So we do not have anything or any keys stored.



168

00:15:48,530 --> 00:15:58,650

I will  store a key, I will  store a list rather with Color and let's name it, let's  provide some of the values.



169

00:16:09,240 --> 00:16:10,500

Hit enter.



170

00:16:10,620 --> 00:16:19,770

So now we have 6 values stored in a key which is called Color and if you want to see all the items which



171

00:16:19,770 --> 00:16:27,180

is inside the Color Key. So we can use L range and the key name which is Color and Starting index which



172

00:16:27,180 --> 00:16:35,870

is going to be 0 and then Ending index.  Since I want to print everything I need to use -1.  so



173

00:16:35,870 --> 00:16:40,280

-1 means is basically print everything in this case.



174

00:16:40,430 --> 00:16:46,440

Okay so if we hit enter,  we can see we have all the information.



175

00:16:46,520 --> 00:16:55,730

Now I'm going to exit by using Quit and then now I'm going to connect to Slave Node.



176

00:16:55,880 --> 00:17:03,700

Okay so we need to change the IP address. Slave Node IP address is 10.128.0.5.  I have change the IP address.



177

00:17:03,770 --> 00:17:05,090

Hit enter.



178

00:17:05,090 --> 00:17:10,850

Now you are connected to the Slave Node. So whatever you have written there on the Master Node, you should



179

00:17:10,850 --> 00:17:14,680

be able to get the same data here on the Slave Node.



180

00:17:15,080 --> 00:17:23,730

So I will do L range and provided the key name and the starting and end range.



181

00:17:23,900 --> 00:17:24,280

Okay.



182

00:17:24,740 --> 00:17:30,120

So once I do, I can see that I have got the same information on the Slave Node also.



183

00:17:30,320 --> 00:17:36,800

Now to verify that it is really a Slave Node and it is not allowing any you know, right connection you



184

00:17:36,800 --> 00:17:40,730

can try to give a or



185

00:17:47,040 --> 00:17:48,580

try issuing an



186

00:18:14,940 --> 00:18:22,170

Now to make sure this is a really a Slave Node, we can actually issue a  Set command. It should give



187

00:18:22,170 --> 00:18:30,550

us an error saying that,  It is a Read Only Replica.  So let's do  a Set command and try to update a key



188

00:18:30,580 --> 00:18:31,740

which is called Product.



189

00:18:32,040 --> 00:18:39,400

And let's try to give a Value Name which is Chair.  Hit enter and you see we are getting the error that this



190

00:18:39,400 --> 00:18:40,600

is a Read Only Replica.



191

00:18:40,990 --> 00:18:41,220

Okay.



192

00:18:41,230 --> 00:18:50,450

So this confirms that this Server or this Node, which we are connected to right now is actually a Slave Node.



193

00:18:50,980 --> 00:18:52,890

Okay so I will quit again from here



194

00:18:55,780 --> 00:19:01,180

and let me clear the screen. Let's do Host name -i



195

00:19:01,800 --> 00:19:08,850

So you see we are actually on Slave Node Server and also now let's see the you know,



196

00:19:12,400 --> 00:19:16,110

existence of Slash.



197

00:19:16,260 --> 00:19:20,700

Basically we want to see whether the dump.rdb file   is created or not. So if you remember



198

00:19:20,700 --> 00:19:25,360

we have given path  of /home/redisadmin



199

00:19:25,560 --> 00:19:27,380

So here we should be able to see



200

00:19:27,410 --> 00:19:28,410

dump.rdb file



201

00:19:28,590 --> 00:19:31,890

Yes we see the file is already available here.



202

00:19:33,130 --> 00:19:33,390

OK



203

00:19:37,080 --> 00:19:43,350

now we are good to mimic you know, Master fail scenario. So we will log into



204

00:19:46,650 --> 00:19:48,760

itpanther02  server.



205

00:19:51,670 --> 00:19:53,830

so now let's verify that we are on



206

00:19:56,810 --> 00:19:58,650

yeah, we are on the Master node.



207

00:19:58,850 --> 00:19:59,200

Okay.



208

00:19:59,200 --> 00:20:01,130

And now I'm going to shut down this server.



209

00:20:10,150 --> 00:20:18,160

So once we do that, we no longer will be able to, basically connect to this session. So I'm going to open



210

00:20:18,160 --> 00:20:19,110

a new session.



211

00:20:21,010 --> 00:20:23,050

Or let me open a Duplicate Session



212

00:20:30,240 --> 00:20:30,540

okay.



213

00:20:30,540 --> 00:20:36,560

So on this session I'm going to switch to Slave



214

00:20:36,590 --> 00:20:36,880

Node.



215

00:20:38,790 --> 00:20:39,360

Okay.



216

00:20:39,360 --> 00:20:45,930

So here if you verify this is a Slave Node and here you can verify this a Master Node.



217

00:20:45,930 --> 00:20:55,240

Now I'm going to do sudo space shutdown and before that let's also do  tail -F on Slave Node. So



218

00:20:55,240 --> 00:20:57,150

we can actually see the error.



219

00:20:57,250 --> 00:21:00,280

Okay when we are shutting down the Master Server.



220

00:21:00,490 --> 00:21:03,030

Okay so let me shut it down.



221

00:21:05,550 --> 00:21:09,900

Okay so shut down command has issued and now this server is going to get shut down.



222

00:21:09,930 --> 00:21:11,780

Now let's see the logs here.



223

00:21:27,630 --> 00:21:29,330

So whatever message you saw here.



224

00:21:29,350 --> 00:21:32,550

Actually this is not related to Redis log.



225

00:21:32,550 --> 00:21:36,450

This is basically because we open the session as a duplicate session.



226

00:21:36,450 --> 00:21:40,440

So this is the message from itpanther02  server.



227

00:21:40,770 --> 00:21:43,050

Anyhow we can run this command again.



228

00:21:43,050 --> 00:21:45,330

So we are able to see the latest logs



229

00:21:50,620 --> 00:21:56,430

Okay so as of now Master server, still is in the process of shutting down.



230

00:21:57,270 --> 00:21:59,640

So we do not see any error here as of now.



231

00:22:05,390 --> 00:22:05,680

Okay.



232

00:22:05,730 --> 00:22:09,280

So now we see that we get the error, which means



233

00:22:14,020 --> 00:22:15,980

that server has been disconnected.



234

00:22:24,760 --> 00:22:31,570

So since we opened it as a Duplicate session or somehow this session is not allowing us to see anything



235

00:22:31,570 --> 00:22:32,390

and this session



236

00:22:32,410 --> 00:22:40,840

Also has went to a  inactive state.  So rather  I will open a new session and then we log into the Slave



237

00:22:40,840 --> 00:22:41,060

Node.



238

00:22:46,050 --> 00:22:51,900

So this is a new session which I have opened and this is a Slave Node.  You can verify the IP address.



239

00:22:52,320 --> 00:22:55,640

Let me close all the previous sessions.



240

00:22:56,480 --> 00:22:58,330

Okay so this is what we have right now.



241

00:23:01,890 --> 00:23:04,940

And just remember that we have shut down the Master server.



242

00:23:04,970 --> 00:23:09,580

So let's verify the logs on Slave server.



243

00:23:15,130 --> 00:23:22,560

Now you see that Slave is getting some time out errors that it is basically not able to connect to Master



244

00:23:22,700 --> 00:23:22,980

node



245

00:23:33,120 --> 00:23:33,420

okay.



246

00:23:33,430 --> 00:23:36,580

So this is an indication that Master is not available.



247

00:23:36,580 --> 00:23:43,120

And also you can use various Redis-cli and use -h and try connecting to the Master Node



248

00:23:51,340 --> 00:23:51,820

you notice



249

00:23:51,820 --> 00:23:56,320

when I hit enter,  I don't see anything or any message.



250

00:23:56,330 --> 00:24:03,870

So basically it has just,  we are not able to connect to this Redis Client,  which is Master Node.



251

00:24:06,640 --> 00:24:08,880

So i press control c to exit



252

00:24:13,360 --> 00:24:17,340

and if we  verify by connecting to Slave Node.



253

00:24:17,450 --> 00:24:23,420

We still can connect to Slave Node and we can see the keys stored here.



254

00:24:28,390 --> 00:24:33,280

And we also can see everything, which is stored here. It is still a Slave Node,  because if you try to update



255

00:24:33,280 --> 00:24:36,750

any value,  you won't be able to do it.



256

00:24:37,070 --> 00:24:46,430

Okay so now let's connect to a New Server which in this case is going to be,  bind address



257

00:24:46,520 --> 00:24:47,870

And here we will do the setup.



258

00:24:54,290 --> 00:24:58,150

Okay so right now we are on Slave Node.



259

00:24:58,250 --> 00:25:05,370

I'm going to do ssh itpanther04 and now if we do Host name -i ,  you can see will log



260

00:25:05,480 --> 00:25:05,780

to



261

00:25:10,090 --> 00:25:12,470

10.128.0.6



262

00:25:12,490 --> 00:25:15,760

Now here right now,  I do not see any Redis  software.



263

00:25:15,760 --> 00:25:22,200

So this is you can assume, it is a fresh server, where we do not have Redis  software also available.



264

00:25:22,200 --> 00:25:24,990

So I'm going to go back to Slave Node.



265

00:25:25,000 --> 00:25:26,710

From there I will copy the software.



266

00:25:27,190 --> 00:25:29,440

And also I will copy dump.rdb



267

00:25:41,270 --> 00:25:41,780

okay.



268

00:25:41,790 --> 00:25:45,560

So here we will do scp -r, let's copy this software



269

00:26:01,660 --> 00:26:04,720

and now we will copy dump.rdb as well.



270

00:26:05,030 --> 00:26:05,350

Okay.



271

00:26:10,990 --> 00:26:19,090

Because if you remember dump.rdb is having the or this  is the basically a snapshot.



272

00:26:19,150 --> 00:26:19,540

Okay.



273

00:26:19,540 --> 00:26:28,230

And before we actually copy this dump.rdb,  we should actually make sure that this is the latest



274

00:26:28,860 --> 00:26:29,580

dump file.



275

00:26:29,790 --> 00:26:32,120

Okay so this is the latest RDB file.



276

00:26:32,370 --> 00:26:38,670

Now  the way to ensure that is, actually you can use a safe command again.



277

00:26:38,730 --> 00:26:46,340

That will make sure that it creates a latest dump.rdb file.  So for that I will connect to



278

00:26:46,340 --> 00:26:53,400

Redis-cli like and provide the Slave IP address.



279

00:27:03,070 --> 00:27:04,230

Syntax was incorrect.



280

00:27:04,240 --> 00:27:07,500

So that's why we couldn't connect okay.



281

00:27:07,510 --> 00:27:12,390

So here I will write or I will hit save command.  Type save.



282

00:27:12,400 --> 00:27:18,820

Hit Enter. Now it replies Okay.  So now it has created the latest dump.rdb file.  So we can quit



283

00:27:18,820 --> 00:27:24,010

from here.  So you can use either Quit command or exit command. Both works the same way.



284

00:27:26,260 --> 00:27:29,910

OK.



285

00:27:30,120 --> 00:27:36,150

Now you see dump.rdb size previously and now there is a difference.  So basically this was, this might



286

00:27:36,150 --> 00:27:38,670

be a little  not up to date.



287

00:27:38,670 --> 00:27:40,500

This is the up to date, most up to date.



288

00:27:40,890 --> 00:27:51,980

So now we are good to copy this software.  So we will copy this dump.rdb to Remote Server



289

00:27:52,070 --> 00:28:00,630

which is itpanther04 and also we'll copy it to the home directory.  Okay.



290

00:28:00,660 --> 00:28:10,350

So this is copied and now we will connect to new server which is itpanther04



291

00:28:10,600 --> 00:28:12,070

You can verify the IP address.



292

00:28:12,070 --> 00:28:14,860

So now we are connected to this New Server.



293

00:28:17,590 --> 00:28:17,930

okay.



294

00:28:17,960 --> 00:28:26,450

So here again go inside where Redis-stable and make sure the configuration is as per the New



295

00:28:26,450 --> 00:28:26,810

Node.



296

00:28:26,960 --> 00:28:27,300

Okay.



297

00:28:27,320 --> 00:28:31,190

So i am opening Redis.conf file and here



298

00:28:31,190 --> 00:28:34,760

make sure whatever the  bind address,



299

00:28:38,690 --> 00:28:44,460

yeah whatever the bind address, IP addresses is. This  should be the new server's IP address.



300

00:28:44,450 --> 00:28:46,880

So here I have changed it from five to six.



301

00:28:47,860 --> 00:28:51,250

Okay because IP address of this server is 6



302

00:28:51,470 --> 00:28:54,640

And if you want to make any changes here in the log file you can make.



303

00:28:54,660 --> 00:28:59,180

But I just follow the standard.  So I'm keeping you in  /tmp/redis.log



304

00:29:02,040 --> 00:29:08,340

and the most important step is, this directory should be pointing to the directory where you have the



305

00:29:08,340 --> 00:29:10,330

latest dump.rdb file.



306

00:29:10,860 --> 00:29:17,430

Because when you start this server it is going to pick that latest dump.rdb to copy everything



307

00:29:17,970 --> 00:29:18,690

and restore.



308

00:29:18,900 --> 00:29:26,010

OK so if it is not able to  find dump.rdb,  it is going to assume that there is no data and it



309

00:29:26,010 --> 00:29:34,830

is just going to start blank server,  basically which will not have any data and after that make sure in the



310

00:29:34,830 --> 00:29:35,610

replica of



311

00:29:35,820 --> 00:29:43,500

Since we copied this software from Slave Node.  So we  have replica of enabled.  We need to disable it, because



312

00:29:43,500 --> 00:29:47,580

we don't want this Sever to become a Slave Node. This ever is going to be a Master Node.



313

00:29:47,620 --> 00:29:47,900

OK.



314

00:29:47,910 --> 00:29:59,520

So I have commented the replica of  line. Ok you can verify that here, in this line. So I will save and exit



315

00:30:06,260 --> 00:30:09,390

and now we can go to src directory and we are good  to



316

00:30:12,490 --> 00:30:13,290

start Redis.



317

00:30:13,390 --> 00:30:13,850

OK.



318

00:30:14,500 --> 00:30:18,940

So again to start Redis, you do ./Redis- server



319

00:30:18,940 --> 00:30:23,010

after going inside src directory.  Let me clear the screen.



320

00:30:24,520 --> 00:30:26,590

And this is the current directory, which we are now



321

00:30:30,820 --> 00:30:36,300

and also provide the full path  of the Redis.conf file.



322

00:30:47,840 --> 00:30:48,180

okay.



323

00:30:48,190 --> 00:30:50,920

Now we can check the logs



324

00:30:57,160 --> 00:30:57,490

OK.



325

00:30:57,520 --> 00:31:05,840

So this server has started properly and also now we can connect to this Server and we can verify that we



326

00:31:05,840 --> 00:31:07,490

have the data restored.



327

00:31:22,040 --> 00:31:22,370

Okay.



328

00:31:22,390 --> 00:31:27,130

So we can see whatever dump.rdb  file was there, it  has restored data from there.



329

00:31:33,790 --> 00:31:34,170

OK.



330

00:31:34,190 --> 00:31:37,050

We see all the data which we had put in Color key.



331

00:31:37,070 --> 00:31:44,890

We can see here,  but please remember right now this node is working as a, you know, independent  Master Node and



332

00:31:44,950 --> 00:31:48,460

still the previously Slave node is not pointing to this new Master Node.



333

00:31:49,240 --> 00:31:56,630

So we need to connect to that previous Slave node, by using redis-cli -h  provide the



334

00:31:56,690 --> 00:32:01,150

IP address of previous Slave node, which is 10.128.0.5



335

00:32:04,120 --> 00:32:13,180

Hit enter and here you need to change this and point it  to the New Node.  So the way to do that is you



336

00:32:13,180 --> 00:32:22,030

Slave of command,  which is slaveof and then you provide the New Master's IP address, which is going to



337

00:32:22,030 --> 00:32:25,690

be 10.128.0.6



338

00:32:26,080 --> 00:32:33,820

And also you provide the Port Name.  So once you hit enter, it says Okay.  Now you can quit from here.



339

00:32:38,080 --> 00:32:46,440

Okay, so now let's log into the New Master, which is on IP 10.128.0.6



340

00:32:49,930 --> 00:32:57,450

and now let's see the value again, which we had previously in the Color Key and now to verify that we are



341

00:32:57,450 --> 00:33:05,630

able to write or perform write operations on the Master Node.  I am going to add some for some more values



342

00:33:05,690 --> 00:33:06,800

into this Color Key.



343

00:33:14,230 --> 00:33:19,000

You see we are successfully able to write more values to this key.



344

00:33:19,080 --> 00:33:25,200

Now I'm going to quit from here and we will go back to the Slave Node and we will see that new data



345

00:33:25,200 --> 00:33:27,210

has been replicated there or  not.



346

00:33:31,560 --> 00:33:35,800

Okay so Slave Node is running at 10.128.0.5



347

00:33:36,160 --> 00:33:41,890

And if I do L push here.  You can see I'm not able to you know, write data



348

00:33:41,890 --> 00:33:42,400

here because



349

00:33:42,390 --> 00:33:51,550

this is a Slave Node.  However I will do L range now  and see what is the new value of Color Key.



350

00:33:51,560 --> 00:33:58,010

Okay,  so now we see list has been updated and now we are having  couple of more items, which we had added.