Error while installing in digital ocean /root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/fibers/future.js:245 throw(ex);

i tried to install
rocket.chat

in my digital ocean cloud hosting alc, but again and again i got the same error

=====================================================================
rocketchat:file: updating npm dependencies -- mkdirp, gridfs-stream, gm...
Unexpected mongo exit code null. Restarting.
=> Exited from signal: SIGKILL

/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/dev_bundle/lib/node_modules/fibers/future.js:245
                                                throw(ex);
                                                      ^
Error: spawn ENOMEM
  at errnoException (child_process.js:1011:11)
  at ChildProcess.spawn (child_process.js:958:11)
  at Object.exports.spawn (child_process.js:746:9)
  at spawnMongod (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/run-mongo.js:40:24)
  at launchOneMongoAndWaitForReadyForInitiate (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/run-mongo.js:414:12)
  at launchMongo (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/run-mongo.js:612:7)
  at [object Object]._.extend._startOrRestart (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/run-mongo.js:712:19)
  at [object Object].<anonymous> (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/run-mongo.js:775:14)
  at runWithEnvironment (/root/.meteor/packages/meteor-tool/.1.1.3.4sddkj++os.linux.x86_64+web.browser+web.cordova/mt-os.linux.x86_64/tools/fiber-helpers.js:139:21)

root@nextdhoom:~/Rocket.Chat# meteor
[[[[[ ~/Rocket.Chat ]]]]]

=====================================================

Searched on the internet but could not find any valid answer

then i realised that it was , since i had purchased a $5 droplet with just 512 memory, it was causing that problem

then i upgraded the droplet to 2GB memory and 40GB SSD disk, and the problem vanished

i was able to successfully install and was able to run the program