/// <summary>
/// Ensures we have at least 1 'slack' server failure. i.e. ensures ntol is such that removing 1 host from the pool
/// (by reboot, shutdown or disable) will succeed.
/// May throw CancelledException if the user says no.
/// </summary>
/// <param name="actionKind">Must be one of Evacuate, Reboot, RebootAndWait or Shutdown. Required so we can show the correct prompt.</param>
protected void MaybeReduceNtolBeforeOp(HostActionKind actionKind)
{
System.Diagnostics.Trace.Assert(actionKind == HostActionKind.Reboot ||
actionKind == HostActionKind.RebootAndWait || actionKind == HostActionKind.Shutdown || actionKind == HostActionKind.Evacuate);
// We may need to drop ntol for this disable to succeed.
Pool pool = Helpers.GetPoolOfOne(Host.Connection);
if (pool != null && pool.ha_enabled)
{
Dictionary <XenRef <VM>, string> config = Helpers.GetVmHaRestartPrioritiesForApi(Helpers.GetVmHaRestartPriorities(pool.Connection, true));
long max = XenAPI.Pool.ha_compute_hypothetical_max_host_failures_to_tolerate(this.Session, config);
long currentNtol = pool.ha_host_failures_to_tolerate;
long targetNtol = Math.Max(0, max - 1);
if (currentNtol > targetNtol)
{
bool cancel = false;
// We need to lower ntol. Ask user.
cancel = (AcceptNTolChanges != null) ? AcceptNTolChanges(this, pool, currentNtol, targetNtol) : false;
if (cancel)
{
throw new CancelledException();
}
// This ensures we can tolerate at least one failure - i.e. the host we're about to disable
XenAPI.Pool.set_ha_host_failures_to_tolerate(this.Session, pool.opaque_ref, targetNtol);
}
}
}
/// <summary>
/// Ensures we have at least 1 'slack' server failure. i.e. ensures ntol is such that removing 1 host from the pool
/// (by reboot, shutdown or disable) will succeed.
/// May throw CancelledException if the user says no.
/// </summary>
/// <param name="actionKind">Must be one of Evacuate, Reboot, RebootAndWait or Shutdown. Required so we can show the correct prompt.</param>
protected void MaybeReduceNtolBeforeOp(HostActionKind actionKind)
{
System.Diagnostics.Trace.Assert(actionKind == HostActionKind.Reboot ||
actionKind == HostActionKind.RebootAndWait || actionKind == HostActionKind.Shutdown||actionKind==HostActionKind.Evacuate);
// We may need to drop ntol for this disable to succeed.
Pool pool = Helpers.GetPoolOfOne(Host.Connection);
if (pool != null && pool.ha_enabled)
{
Dictionary<XenRef<VM>, string> config = Helpers.GetVmHaRestartPrioritiesForApi(Helpers.GetVmHaRestartPriorities(pool.Connection, true));
long max = XenAPI.Pool.ha_compute_hypothetical_max_host_failures_to_tolerate(this.Session, config);
long currentNtol = pool.ha_host_failures_to_tolerate;
long targetNtol = Math.Max(0, max - 1);
if (currentNtol > targetNtol)
{
bool cancel = false;
// We need to lower ntol. Ask user.
cancel = (AcceptNTolChanges != null) ? AcceptNTolChanges(this, pool, currentNtol, targetNtol) : false;
if (cancel)
{
throw new CancelledException();
}
// This ensures we can tolerate at least one failure - i.e. the host we're about to disable
XenAPI.Pool.set_ha_host_failures_to_tolerate(this.Session, pool.opaque_ref, targetNtol);
}
}
}
