The error below is seen frequently on maps1* servers. Some more investigation required to understand if there is an issue (and what the issue is) and either fix the issue or reduce the log level / verbosity.
[2017-02-21T15:14:53.500Z] ERROR: kartotherian/24 on maps1001: GroupId not available (err.levelPath=error) kartotherian: GroupId not available at /srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/kartotherian-snapshot/lib/mapdataLoader.js:53:19 at tryCatcher (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/util.js:16:23) at Promise._settlePromiseFromHandler (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:510:31) at Promise._settlePromise (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:567:18) at Promise._settlePromise0 (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:612:10) at Promise._settlePromises (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:691:18) at Promise._fulfill (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:636:18) at Promise._resolveCallback (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:431:57) at Promise._settlePromiseFromHandler (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:522:17) at Promise._settlePromise (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:567:18) at Promise._settlePromise0 (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:612:10) at Promise._settlePromises (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:691:18) at Promise._fulfill (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:636:18) at PromiseArray._resolve (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise_array.js:125:19) at PromiseArray._promiseFulfilled (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise_array.js:143:14) at Promise._settlePromise (/srv/deployment/kartotherian/deploy-cache/revs/abc731d9ad76337720e0741016001d590beb9492/node_modules/bluebird/js/release/promise.js:572:26)