In a computer-implemented method for proactive handling of an index update, a data point is received at an ingestion node of a time series data monitoring system. It is determined whether an update to a local index of the ingestion node is necessitated based on the data point and the local index. Provided the update to the local index is necessitated, an index entry corresponding to the data point in the local index is updated based on the data point. The index entry corresponding to the data point is marked with a volatile indicator, the volatile indicator indicating that receipt of an index update to a corresponding index entry at a durable index of the time series data monitoring system is unconfirmed. The index update to the durable index corresponding to the data point is initiated.