Stacktrace (most recent call first):

  bson/hash.rb:77:in `readbyte'
    while (type = bson.readbyte.chr) != NULL_BYTE
  bson/hash.rb:77:in `from_bson'
    while (type = bson.readbyte.chr) != NULL_BYTE
  moped/connection.rb:133:in `block (2 levels) in read'
    ::BSON::Document.from_bson(buffer)
  moped/connection.rb:132:in `times'
    reply.documents = reply.count.times.map do
  moped/connection.rb:132:in `each'
    reply.documents = reply.count.times.map do
  moped/connection.rb:132:in `map'
    reply.documents = reply.count.times.map do
  moped/connection.rb:132:in `block in read'
    reply.documents = reply.count.times.map do
  moped/connection.rb:224:in `with_connection'
    yield @sock
  moped/connection.rb:114:in `read'
    with_connection do |socket|
  moped/protocol/query.rb:213:in `receive_replies'
    connection.read
  moped/connection.rb:152:in `block in receive_replies'
    operation.receive_replies(self)
  moped/connection.rb:151:in `map'
    operations.map do |operation|
  moped/connection.rb:151:in `receive_replies'
    operations.map do |operation|
  moped/node.rb:591:in `block (2 levels) in flush'
    replies = conn.receive_replies(operations)
  moped/node.rb:181:in `block in ensure_connected'
    yield(conn)
  moped/node.rb:115:in `block in connection'
    yield(conn)
  connection_pool.rb:58:in `with'
    yield conn
  moped/node.rb:114:in `connection'
    pool.with do |conn|
  moped/node.rb:177:in `ensure_connected'
    connection do |conn|
  moped/node.rb:589:in `block in flush'
    ensure_connected do |conn|
  moped/node.rb:617:in `block in logging'
    yield if block_given?
  active_support/notifications.rb:159:in `block in instrument'
    instrumenter.instrument(name, payload) { yield payload if block_given? }
  active_support/notifications/instrumenter.rb:20:in `instrument'
    yield payload
  active_support/notifications.rb:159:in `instrument'
    instrumenter.instrument(name, payload) { yield payload if block_given? }
  moped/instrumentable.rb:31:in `instrument'
    instrumenter.instrument(name, payload, &block)
  moped/node.rb:616:in `logging'
    instrument(TOPIC, prefix: "  MOPED: #{address.resolved}", ops: operations) do
  newrelic_moped/instrumentation.rb:40:in `block in logging_with_newrelic_trace'
    command = Proc.new { logging_without_newrelic_trace(operations, &blk) }
  newrelic_moped/instrumentation.rb:49:in `call'
    res = command.call
  newrelic_moped/instrumentation.rb:49:in `block in logging_with_newrelic_trace'
    res = command.call
  new_relic/agent/method_tracer.rb:281:in `trace_execution_scoped'
    result = yield
  newrelic_moped/instrumentation.rb:46:in `logging_with_newrelic_trace'
    self.class.trace_execution_scoped(metrics) do
  moped/node.rb:587:in `flush'
    logging(operations) do
  moped/node.rb:391:in `process'
    flush([[ operation, callback ]])
  moped/operation/read.rb:48:in `execute'
    node.process(operation) do |reply|
  moped/node.rb:648:in `read'
    Operation::Read.new(operation).execute(self)
  moped/node.rb:411:in `query'
    read(Protocol::Query.new(database, collection, selector, options))
  moped/query.rb:128:in `block in first'
    node.query(
  moped/cluster.rb:249:in `block in with_primary'
    return yield(node)
  moped/node.rb:204:in `block in ensure_primary'
    yield(self)
  moped/executable.rb:25:in `execute'
    yield(self)
  moped/node.rb:203:in `ensure_primary'
    execute(:ensure_primary) do
  moped/cluster.rb:248:in `with_primary'
    node.ensure_primary do
  moped/read_preference/primary.rb:55:in `block in with_node'
    cluster.with_primary(&block)
  moped/read_preference/selectable.rb:65:in `call'
    block.call
  moped/read_preference/selectable.rb:65:in `with_retry'
    block.call
  moped/read_preference/primary.rb:54:in `with_node'
    with_retry(cluster) do
  moped/query.rb:127:in `first'
    reply = read_preference.with_node(cluster) do |node|
  mongoid/query_cache.rb:187:in `block in first_with_cache'
    first_without_cache
  mongoid/query_cache.rb:135:in `with_cache'
    return yield unless QueryCache.enabled?
  mongoid/query_cache.rb:186:in `first_with_cache'
    with_cache(:first) do
  new_relic/agent/instrumentation/sinatra.rb:151:in `dispatch_and_notice_errors_with_newrelic'
    dispatch_without_newrelic
  new_relic/agent/instrumentation/sinatra.rb:146:in `block in dispatch_with_newrelic'
    dispatch_and_notice_errors_with_newrelic
  new_relic/agent/instrumentation/controller_instrumentation.rb:335:in `perform_action_with_newrelic_trace'
    yield
  new_relic/agent/instrumentation/sinatra.rb:143:in `dispatch_with_newrelic'
    perform_action_with_newrelic_trace(:category => :sinatra,
  sinatra/base.rb:898:in `block in call!'
    invoke { dispatch! }
  sinatra/base.rb:1058:in `block in invoke'
    res = catch(:halt) { yield }
  sinatra/base.rb:1058:in `catch'
    res = catch(:halt) { yield }
  sinatra/base.rb:1058:in `invoke'
    res = catch(:halt) { yield }
  sinatra/base.rb:898:in `call!'
    invoke { dispatch! }
  sinatra/base.rb:886:in `call'
    dup.call!(env)
  new_relic/rack/error_collector.rb:55:in `call'
    @app.call(env)
  new_relic/rack/browser_monitoring.rb:27:in `call'
    result = @app.call(env)   # [status, headers, response]
  new_relic/rack/agent_hooks.rb:32:in `call'
    result = @app.call(env)
  rack/protection/xss_header.rb:18:in `call'
    status, headers, body = @app.call(env)
  rack/protection/path_traversal.rb:16:in `call'
    app.call env
  rack/protection/json_csrf.rb:18:in `call'
    status, headers, body = app.call(env)
  rack/protection/base.rb:49:in `call'
    result or app.call(env)
  rack/protection/base.rb:49:in `call'
    result or app.call(env)
  rack/protection/frame_options.rb:31:in `call'
    status, headers, body        = @app.call(env)
  rack/nulllogger.rb:9:in `call'
    @app.call(env)
  rack/head.rb:11:in `call'
    status, headers, body = @app.call(env)
  sinatra/base.rb:180:in `call'
    result, callback = app.call(env), env['async.callback']
  sinatra/base.rb:2014:in `call'
    @stack.call(env)
  sinatra/base.rb:1478:in `block in call'
    synchronize { prototype.call(env) }
  sinatra/base.rb:1788:in `synchronize'
    yield
  sinatra/base.rb:1478:in `call'
    synchronize { prototype.call(env) }
  rack/urlmap.rb:65:in `block in call'
    return app.call(env)
  rack/urlmap.rb:50:in `each'
    @mapping.each do |host, location, match, app|
  rack/urlmap.rb:50:in `call'
    @mapping.each do |host, location, match, app|
  librato/rack.rb:94:in `process_request'
    response = @app.call(env)
  trakio/api/librato_middleware.rb:28:in `call'
    response, duration = process_request(env)
  new_relic/rack/error_collector.rb:55:in `call'
    @app.call(env)
  new_relic/rack/agent_hooks.rb:32:in `call'
    result = @app.call(env)
  raven/integrations/rack.rb:61:in `call'
    response = @app.call(env)
  trakio/api/consumer/worker.rb:73:in `work'
    self.class.api_application.call(env)
  sneakers/worker.rb:58:in `block (3 levels) in do_work'
    res = work(msg)
  sneakers/metrics/null_metrics.rb:8:in `call'
    block.call
  sneakers/metrics/null_metrics.rb:8:in `timing'
    block.call
  sneakers/worker.rb:54:in `block (2 levels) in do_work'
    metrics.timing("work.#{self.class.name}.time") do
  timeout.rb:91:in `block in timeout'
    return yield(sec)
  timeout.rb:35:in `block in catch'
    ::Kernel.catch(exc) {yield exc}
  timeout.rb:35:in `catch'
    ::Kernel.catch(exc) {yield exc}
  timeout.rb:35:in `catch'
    ::Kernel.catch(exc) {yield exc}
  timeout.rb:106:in `timeout'
    bt = ExitException.catch(message, &bl)
  sneakers/worker.rb:53:in `block in do_work'
    Timeout.timeout(@timeout_after) do
  thread/pool.rb:56:in `call'
    @block.call(*@arguments)
  thread/pool.rb:56:in `execute'
    @block.call(*@arguments)
  thread/pool.rb:384:in `block (2 levels) in spawn_thread'
    task.execute(thread)
  thread/pool.rb:351:in `loop'
    loop do
  thread/pool.rb:351:in `block in spawn_thread'
    loop do