[server] Make connection pooler configurable and set better default values
Drop the configuration connections-pool-size and add new configurations options:
* connections-pool-min-size. Set to 0 by default so we open connections only
when needed. This avoid opening min-size*processes connections at startup,
which is, it think, a good default.
* connections-pool-max-size. Set to 0 (unlimited) by default, so we move the
bottleneck to postgresql.
* connections-idle-timeout. Set to 10 minutes. I don't have arguments about
this except that this is the default in pgbouncer.
function datetuple(d) {
return [d.getFullYear(), d.getMonth()+1, d.getDate(),
d.getHours(), d.getMinutes()];
}
function pprint(obj) {
print('{');
for(k in obj) {
print(' ' + k + ' = ' + obj[k]);
}
print('}');
}
function arrayrepr(array) {
return '[' + array.join(', ') + ']';
}
function assertArrayEquals(array1, array2) {
if (array1.length != array2.length) {
throw new crosscheck.AssertionFailure(array1.join(', ') + ' != ' + array2.join(', '));
}
for (var i=0; i<array1.length; i++) {
if (array1[i] != array2[i]) {
throw new crosscheck.AssertionFailure(arrayrepr(array1) + ' and ' + arrayrepr(array2)
+ ' differs at index ' + i);
}
}
}