tree 48b35cd80a82b170699919396489c4a8746566a4
parent b9197a057a6cb1129f29cd21ca11d1bb043666d1
author Olav Loite <koloite@gmail.com> 1567700149 +0200
committer Knut Olav Løite <koloite@gmail.com> 1571380736 +0000

spanner: use BatchCreateSessions to init pool

Adds a session client that is responsible for creating
sessions for the session pool and others that need a
session. The session client encapsulates the details of
spreading all sessions over all available gRPC channels.

The session client also contains functionality for creating
batches of sessions that can be used by the session pool to
speed up initialization of a large session pool or to create
a burst of sessions. These batches are also automatically
evenly distributed over all available channels.

The default MinOpened sessions configuration is changed to
100. The session pool uses the BatchCreateSessions method
to initialize the pool if MinOpened > 0.

Updates #1566.

Change-Id: I13e6fbc321688cdbd396913e4f4c01aa8631fb2c
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/45111
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jean de Klerk <deklerk@google.com>