SyncedCron not running, timing out DB connection, high connection IDs

Hi folks, posting here in case anyone’s dealt with something similar. I have a Meteor app where cron was running every two hours until a couple days ago. Since then I’ve started seeing the errors below. One thing that has me curious is why the connection numbers are so high (starts at 378012). The database appears to be online when I query it from MongoChef. Any pointers as to where I should go from here? Thanks!

15:55:41 0|main | Exception in setInterval callback: MongoError: connection 378012 to app123:27017 timed out
15:55:41 0|main | at Object.Future.wait (/home/meteorapp/build/bundle/programs/server/node_modules/fibers/future.js:449:15)
15:55:41 0|main | at [object Object]. (packages/meteor.js:213:24)
15:55:41 0|main | at [object Object].MongoConnection.(anonymous function) [as update] (packages/mongo/mongo_driver.js:778:49)
15:55:41 0|main | at Object. (packages/matb33_collection-hooks.js:504:27)
15:55:41 0|main | at Object.collection.(anonymous function) [as update] (packages/matb33_collection-hooks.js:146:21)
15:55:41 0|main | at [object Object].update (packages/mongo/collection.js:588:29)
15:55:41 0|main | at AccountsServer.Ap.expireTokens (packages/accounts-base/accounts_server.js:1117:14)
15:55:41 0|main | at packages/accounts-base/accounts_server.js:1206:14
15:55:41 0|main | at [object Object].
.extend.withValue (packages/meteor.js:1122:17)
15:55:41 0|main | at packages/meteor.js:445:45
15:55:41 0|main | - - - - -
15:55:41 0|main | at Function.MongoError.create (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/error.js:29:11)
15:55:41 0|main | at Socket. (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/connection.js:186:20)
15:55:41 0|main | at Socket.g (events.js:260:16)
15:55:41 0|main | at emitNone (events.js:67:13)
15:55:41 0|main | at Socket.emit (events.js:166:7)
15:55:41 0|main | at Socket._onTimeout (net.js:333:8)
15:55:41 0|main | at _runOnTimeout (timers.js:524:11)
15:55:41 0|main | at makeTimerTimeout (timers.js:515:3)
15:55:41 0|main | at Timer.unrefTimeout (timers.js:584:5)
16:00:30 0|main | Exception in setTimeout callback: MongoError: connection 378013 to app123:27017 timed out
16:00:30 0|main | at Object.Future.wait (/home/meteorapp/build/bundle/programs/server/node_modules/fibers/future.js:449:15)
16:00:30 0|main | at [object Object]. (packages/meteor.js:213:24)
16:00:30 0|main | at [object Object].MongoConnection.(anonymous function) [as insert] (packages/mongo/mongo_driver.js:778:49)
16:00:30 0|main | at Object. (packages/matb33_collection-hooks.js:395:18)
16:00:30 0|main | at Object.collection.(anonymous function) [as insert] (packages/matb33_collection-hooks.js:146:21)
16:00:30 0|main | at [object Object].insert (packages/mongo/collection.js:524:37)
16:00:30 0|main | at packages/percolate_synced-cron.js:227:41
16:00:30 0|main | at scheduleTimeout (packages/percolate_synced-cron.js:290:7)
16:00:30 0|main | at packages/percolate_synced-cron.js:338:42
16:00:30 0|main | at [object Object].
.extend.withValue (packages/meteor.js:1122:17)
16:00:30 0|main | - - - - -
16:00:30 0|main | at Function.MongoError.create (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/error.js:29:11)
16:00:30 0|main | at Socket. (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/connection.js:186:20)
16:00:30 0|main | at Socket.g (events.js:260:16)
16:00:30 0|main | at emitNone (events.js:67:13)
16:00:30 0|main | at Socket.emit (events.js:166:7)
16:00:30 0|main | at Socket._onTimeout (net.js:333:8)
16:00:30 0|main | at _runOnTimeout (timers.js:524:11)
16:00:30 0|main | at makeTimerTimeout (timers.js:515:3)
16:00:30 0|main | at Timer.unrefTimeout (timers.js:584:5)
16:00:30 0|main | Exception in setTimeout callback: MongoError: connection 380158 to app123:27017 timed out
16:00:30 0|main | at Object.Future.wait (/home/meteorapp/build/bundle/programs/server/node_modules/fibers/future.js:449:15)
16:00:30 0|main | at [object Object]. (packages/meteor.js:213:24)
16:00:30 0|main | at [object Object].MongoConnection.(anonymous function) [as insert] (packages/mongo/mongo_driver.js:778:49)
16:00:30 0|main | at Object. (packages/matb33_collection-hooks.js:395:18)
16:00:30 0|main | at Object.collection.(anonymous function) [as insert] (packages/matb33_collection-hooks.js:146:21)
16:00:30 0|main | at [object Object].insert (packages/mongo/collection.js:524:37)
16:00:30 0|main | at packages/percolate_synced-cron.js:227:41
16:00:30 0|main | at scheduleTimeout (packages/percolate_synced-cron.js:290:7)
16:00:30 0|main | at packages/percolate_synced-cron.js:338:42
16:00:30 0|main | at [object Object].
.extend.withValue (packages/meteor.js:1122:17)
16:00:30 0|main | - - - - -
16:00:30 0|main | at Function.MongoError.create (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/error.js:29:11)
16:00:30 0|main | at Socket. (/home/meteorapp/build/bundle/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/connection.js:186:20)
16:00:30 0|main | at Socket.g (events.js:260:16)
16:00:30 0|main | at emitNone (events.js:67:13)
16:00:30 0|main | at Socket.emit (events.js:166:7)
16:00:30 0|main | at Socket._onTimeout (net.js:333:8)
16:00:30 0|main | at _runOnTimeout (timers.js:524:11)
16:00:30 0|main | at _makeTimerTimeout (timers.js:515:3)
16:00:30 0|main | at Timer.unrefTimeout (timers.js:584:5)