Building a high availability steemd node for web apis

If you're interested in building a steemd node for use with a web application, this is meant to serve as your guide. I will attempt to repost this guide occasionally with updates as requirements/steps change (since editing doesn't work past 12 hrs).

Running a load balanced steemd node for the web apis

Running a node for the web is slightly different than a node you'd use for mining or as a witness. We need all of the features available through the API to serve out every piece of information possible. Many mining/witness nodes turn most of these options off to reduce load on the server.

For a web node, we want all of these enabled! The plugins this guide will enable are as follows:

  • database_api
  • login_api
  • market_history_api
  • tags_api
  • follow_api
  • network_broadcast_api(thanks for the tip @rainman)

In the end, your nodes will run as a load balanced websocket server on port 80 (or 443 if you install a ssl cert, not covered here). Both steemstats and piston's API's follow these conventions.

Current hardware requirements:

As of 8/8, the hardware requirements are as follows. I will attempt to recreate this post with best practices over the coming months as requirements increase.

Dual web node:

  • 4 vCPU
  • 16gb RAM (may exceed this soon)
  • Lots of bandwidth to spare (my node uses between 4mb-25mb+ a second)

If you choose to run just a single node, you can effectively cut those requirements in half.

Assumptions

  1. You have a linux server
  2. The linux os is already installed
  3. You have remote access to the server
  4. You have permissions to install software (you may need to add sudo to some of these commands)
  5. You have a basic understanding of system administration

Building steemd, twice.

This configuration runs two instances of steemd for load balancing and failover purposes. If one of the nodes goes down, the other node should still be available to take requests. This will only build the steemd application (thanks to @rainman for the tip here).

If you're interested in compiling the code faster, replace the 4 in -j4 with the number of vCPUs your machine has.

Building node #1

cd ~ git clone https://github.com/steemit/steem.git steem1 cd steem1 git submodule update --init --recursive cmake -DCMAKE_BUILD_TYPE=Release CMakeLists.txt make -j4 steemd

Building node #2

cd ~ git clone https://github.com/steemit/steem.git steem2 cd steem2 git submodule update --init --recursive cmake -DCMAKE_BUILD_TYPE=Release CMakeLists.txt make -j4 steemd

Configuring steemd

Before we start running anything, we need to configure our two steemd nodes. Listed below are two configuration examples, one for each node, where the only difference is the rpc-endpoint port number.


steemd node #1

~/steem1/programs/steemd/witness_node_data_dir/config.ini

``` rpc-endpoint = 127.0.0.1:5090

seed-node=52.38.66.234:2001 seed-node=52.37.169.52:2001 seed-node=52.26.78.244:2001 seed-node=192.99.4.226:2001 seed-node=46.252.27.1:1337 seed-node=81.89.101.133:2001 seed-node=52.4.250.181:39705 seed-node=85.214.65.220:2001 seed-node=104.199.157.70:2001 seed-node=104.236.82.250:2001 seed-node=104.168.154.160:40696 seed-node=162.213.199.171:34191 seed-node=seed.steemed.net:2001 seed-node=steem.clawmap.com:2001 seed-node=seed.steemwitness.com:2001 seed-node=steem-seed1.abit-more.com:2001

enable-plugin = accounthistory enable-plugin = follow enable-plugin = markethistory enable-plugin = private_message enable-plugin = tags

public-api = databaseapi loginapi markethistoryapi tagsapi followapi ```


steemd node #2

~/steem2/programs/steemd/witness_node_data_dir/config.ini

``` rpc-endpoint = 127.0.0.1:5091

seed-node=52.38.66.234:2001 seed-node=52.37.169.52:2001 seed-node=52.26.78.244:2001 seed-node=192.99.4.226:2001 seed-node=46.252.27.1:1337 seed-node=81.89.101.133:2001 seed-node=52.4.250.181:39705 seed-node=85.214.65.220:2001 seed-node=104.199.157.70:2001 seed-node=104.236.82.250:2001 seed-node=104.168.154.160:40696 seed-node=162.213.199.171:34191 seed-node=seed.steemed.net:2001 seed-node=steem.clawmap.com:2001 seed-node=seed.steemwitness.com:2001 seed-node=steem-seed1.abit-more.com:2001

enable-plugin = accounthistory enable-plugin = follow enable-plugin = markethistory enable-plugin = private_message enable-plugin = tags

public-api = databaseapi loginapi markethistoryapi tagsapi followapi ```

Downloading a snapshot of the blockchain

@fydel offers up a snapshot of the blockchain to help you get sync'd faster. You'll need to download this and place it in the appropriate folders to get started.

You need to do this for each individual node you are running, in both steem1 and steem2 folders.

Automatically starting steemd on boot

It's important to ensure your node is running 24/7. If you're running ubuntu, @steemed wrote a guide that helps you configure it with ubuntu.

You'll have to create two of these, one for each steem node you're setting up. I'd recommend naming them as follows:

  • /etc/init/steem1
  • /etc/init/steem2

Once you have the startup scripts created, start steem1 and start steem2 should start both of your nodes. If you'd like to monitor the progress of both nodes simultaneously, you can use:

tail -f path/to/steem1/programs/steemd/debug.log -f path/to/steem2/programs/steemd/debug.log

You will see the nodes replaying the blockchain and once they are ready, you will see lines like this appear:

2163510ms th_a application.cpp:439 handle_block ] Got 2 transactions from network on block 3913580

As more scripts for different distros are created, I'll start adding links to them here or in the next iteration of this guide.

Configuring nginx as your load balancer

I won't go into installing nginx, as you should probably have a basic understanding of how to do this yourself. If you're looking for a package, nginx provides a package for most popular distros.

What we will need though is to configure nginx a little bit. First up, the basic nginx configuration:

nginx config:

/etc/nginx/nginx.conf

``` events { worker_connections 768; }

http { sendfile on; tcpnopush on; tcpnodelay on; keepalivetimeout 65; typeshashmaxsize 2048;

include /etc/nginx/mime.types; default_type application/octet-stream;

accesslog /var/log/nginx/access.log; errorlog /var/log/nginx/error.log;

gzip on; gzip_disable "msie6";

limitreqzone $binaryremoteaddr zone=ws:10m rate=1r/s;

include /etc/nginx/conf.d/.conf; include /etc/nginx/sites-enabled/; } ```

Most of this should already exist in your nginx configuration, but note the limit_req_zone line towards the bottom. This is a measure to help prevent overloading your node by setting up some request throttling.

One more file needs to be added to finish off this configuration, the actual file inside of /etc/nginx/sites-enabled. If this server isn't going to be used for anything else, remove all of the default configurations from that folder and add the following:

nginx vhost config:

/etc/nginx/sites-enabled/default.conf

``` upstream websockets { server 127.0.0.1:5090; server 127.0.0.1:5091; }

server { listen 80; server_name _; root /var/www/html/;

keepalive_timeout 65;
keepalive_requests 100000;
sendfile on;
tcp_nopush on;
tcp_nodelay on;

location ~ ^(/|/ws) {
    limit_req zone=ws burst=5;
    access_log off;
    proxy_pass http://websockets;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_next_upstream error timeout invalid_header http_500;
    proxy_connect_timeout 2;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}

} ```

Reload nginx with service nginx reload and your server should now be responding on port 80 with the steemd nodes you just created. If you load it with a web browser, or just curl http://localhost it should return:

``` 11 eofexception: End Of File stringstream {} tha sstream.cpp:109 peek

{"str":""}
th_a  json.cpp:478 from_string

```

(which is totally ok, as your web browser isn't issuing the proper request)

Congrats!

You're now running a fully featured web node that will return content, following information, tags, account history and plenty of other information! Go forth, build awesome things, and help make the steem community even greater! :)

Something missing?

If you know of something that should be included in this guide, please let me know. I'm looking to help build a comprehensive guide so others can start hosting their own web APIs.

$ 388.472 SBD
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