chain-cosmos-sdk.js: shuffle rpcaddresses

lib/ag-solo/chain-cosmos-sdk.js

@@ -4,7 +4,6 @@ import { execFile } from 'child_process';
 import djson from 'deterministic-json';
 import { createHash } from 'crypto';
 import connect from 'lotion-connect';
-import { Readable } from 'stream';
 
 const HELPER = 'ag-cosmos-helper';
 
@@ -35,6 +34,18 @@ export async function connectToChain(
   // would live in the build tree along with bin/ag-solo . But for now we
   // assume that 'ag-cosmos-helper' is on $PATH somewhere.
 
+  // Shuffle our rpcAddresses, to help distribute load.
+  // Modern version of Fisher-Yates shuffle algorithm (in-place).
+  function shuffle(a) {
+    for (let i = a.length - 1; i > 0; i -= 1) {
+      const j = Math.floor(Math.random() * (i + 1));
+      const x = a[i];
+      a[i] = a[j];
+      a[j] = x;
+    }
+  }
+  shuffle(rpcAddresses);
+
   // TODO: --chain-id matches something in the genesis block, should we
   // include it in the arguments to `css-solo set-gci-ingress`? It's included
   // in the GCI, but if we also need it to establish an RPC connection, then