github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/kv/kvserver/closedts/minprop/doc.go (about)

     1  // Copyright 2018 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  // Package minprop exports a main data structure, Tracker, which checkpoints
    12  // closed timestamps and associated Raft Lease Applied indexes positions for
    13  // which (under additional conditions) it is legal to serve follower reads. It
    14  // does so by maintaining a 'next' timestamp above which new command evaluations
    15  // are forced, and by tracking when all in-flight evaluations below this
    16  // timestamp have completed (at which point a call to the Close method succeeds:
    17  // 'next' becomes closed, and a new 'next' is initialized with a future
    18  // timestamp).
    19  //
    20  // In-flight command evaluations are tracked via the Track method which acquires
    21  // a reference with the tracker, returns a minimum timestamp to be used for the
    22  // proposal evaluation, and provides a closure that releases the reference with
    23  // a lease applied index used for the proposal.
    24  package minprop