Install tntapi cluster¶

Install and configure the tntapi component as follows:

Install tntapi on designated hosts. Tarantool will be installed automatically along it.
```
sudo apt-get update
sudo apt-get install findface-tarantool-server
```
Create tntapi shards on each tntapi host. To learn how to shard, let’s consider a case-study of a cluster environment containing 4 database hosts. We’ll create 4 shards on each.
Important

When creating shards in large installations, observe the following rules:
1. 1 tntapi shard can handle approximately 10,000,000 faces.
2. The number of shards on a single host should not exceed the number of its physical processor cores minus 1.
Disable the Tarantool example service autostart and stop the service. Do so for all the 4 hosts.
```
sudo systemctl disable tarantool@example && sudo systemctl stop tarantool@example
```
Disable the shard created by default. Do so for all the 4 hosts.
```
sudo systemctl disable tarantool@FindFace
```
Write a bash script shard.sh that will automatically create configuration files for all shards on a particular host. Do so for the 4 hosts. Use the following script as a base for your own code. The exemplary script creates 4 shards listening to the ports: tntapi 33001..33004 and http 8001..8004.
Important

The script below creates configuration files based on the default configuration settings stored in the file /etc/tarantool/instances.enabled/FindFace.lua. We strongly recommend you not to add or edit anything in the default file, except the maximum memory usage (memtx_memory) and the NTLS IP address required for the tntapi licensing. The maximum memory usage should be set in bytes for each shard, depending on the number of faces a shard handles, at the rate roughly 1280 byte per face.

Open the configuration file:
```
sudo vi /etc/tarantool/instances.enabled/FindFace.lua
```
Edit the value due the number of faces a shard handles. The value 1.2*1024*1024*1024 corresponds to 1,000,000 faces:
```
memtx_memory = 1.2*1024*1024*1024,
```
Specify the NTLS IP address if NTLS is remote:
```
FindFace.start(“127.0.0.1”, 8001, {license_ntls_server=“192.168.113.2:3133”})
```
```
#!/bin/sh
set -e

for I in `seq 1 4`; do
       TNT_PORT=$((33000+$I)) &&
       HTTP_PORT=$((8000+$I)) &&
       sed "
               s#/opt/ntech/var/lib/tarantool/default#/opt/ntech/var/lib/tarantool/shard_$I#g;
               s/listen = .*$/listen = '127.0.0.1:$TNT_PORT',/;
               s/\"127.0.0.1\", 8001,/\"0.0.0.0\", $HTTP_PORT,/;
       " /etc/tarantool/instances.enabled/FindFace.lua > /etc/tarantool/instances.enabled/FindFace_shard_$I.lua;

       mkdir -p /opt/ntech/var/lib/tarantool/shard_$I/snapshots
       mkdir -p /opt/ntech/var/lib/tarantool/shard_$I/xlogs
       mkdir -p /opt/ntech/var/lib/tarantool/shard_$I/index
       chown -R tarantool:tarantool /opt/ntech/var/lib/tarantool/shard_$I
       echo "Shard #$I inited"
done;
```
Tip

Download the exemplary script.
Run the script from the home directory.
```
sudo sh ~/shard.sh
```

Check the configuration files created.

ls /etc/tarantool/instances.enabled/

##example.lua FindFace.lua FindFace_shard_1.lua FindFace_shard_2.lua FindFace_shard_3.lua FindFace_shard_4.lua

Launch all the 4 shards. Do so on each host.

for I in `seq 1 4`; do sudo systemctl enable tarantool@FindFace_shard_$I; done;
for I in `seq 1 4`; do sudo systemctl start tarantool@FindFace_shard_$I; done;

Retrieve the shards status.

sudo systemctl status tarantool@FindFace*

You should get the following output:

tarantool@FindFace_shard_3.service - Tarantool Database Server
Loaded: loaded (/lib/systemd/system/tarantool@.service; disabled; vendor preset: enabled)
Active: active (running) since Tue 2017-01-10 16:22:07 MSK; 32s ago
...
tarantool@FindFace_shard_2.service - Tarantool Database Server
Loaded: loaded (/lib/systemd/system/tarantool@.service; disabled; vendor preset: enabled)
Active: active (running) since Tue 2017-01-10 16:22:07 MSK; 32s ago
...
tarantool@FindFace_shard_1.service - Tarantool Database Server
Loaded: loaded (/lib/systemd/system/tarantool@.service; disabled; vendor preset: enabled)
Active: active (running) since Tue 2017-01-10 16:22:07 MSK; 32s ago
...
tarantool@FindFace_shard_4.service - Tarantool Database Server
Loaded: loaded (/lib/systemd/system/tarantool@.service; disabled; vendor preset: enabled)
Active: active (running) since Tue 2017-01-10 16:22:07 MSK; 32s ago
...

Tip

You can view the tntapi logs by executing:

sudo tail -f /var/log/tarantool/FindFace_shard_{1,2,3,4}.log

On the findface-facenapi host, create a file tntapi_cluster.json containing the addresses and ports of all the shards. Distribute available shards evenly over ~1024 cells in one line. Click here to see the file for 4 hosts with 4 shards on each.
Tip

You can create tntapi_cluster.json as follows:
1. Create a file that lists all the shards, each shard with a new line (click here to view the example).
  
  sudo vi s.txt
2. Run the script below (click here to view the script). As a result, a new file tntapi_cluster.json will be created and contain a list of all shards distributed evenly over 1024 cells.
cat s.txt | perl -lane 'push(@s,$_); END{$m=1024; $t=scalar @s;for($i=0;$i<$m;$i++){$k=int($i*$t/$m); push(@r,"\"".$s[$k]."\"")} print "[[".join(", ",@r)."]]"; }' > tntapi_cluster.json
Move tntapi_cluster.json to the directory /etc/.

Important

You will have to uncomment and specify the path to tntapi_cluster.json when configuring network.