Public Member Functions
	Server (int thread_id, int group_id, int server_id)

void	Setup (const UpdaterProto &proto, const std::vector< int > &slice2group, const std::vector< int > &slice2server)

void	Run ()

const int	grp_id () const

const int	id () const

Protected Member Functions
virtual Msg *	HandleGet (Msg **msg)
	Process GET request. More...

const std::vector< Msg * >	HandleUpdate (Msg **msg)
	Process Update request. More...

virtual Msg *	HandlePut (Msg **msg)
	Process PUT request. More...

virtual Msg *	HandleSyncRequest (Msg **msg)
	Handle sync request from other server groups. More...

void	HandleSyncResponse (Msg **msg)
	Handle sync response. More...

Protected Attributes
int	thread_id_

int	grp_id_

int	id_

Updater *	updater_
	map from slice ID to slice and deleted in the destructor

std::unordered_map< int, ParamEntry * >	shard_

std::vector< int >	slice2group_

std::vector< int >	slice2server_
	num of updates from last sync with master server group for a param/slice

std::vector< int >	nUpdates_
	num of sync requests that have not been responded

std::vector< int >	nPendingSync_

std::vector< Blob< float > >	last_sync_

std::unordered_map< int, std::vector< Msg * > >	buffer_requests_

Member Function Documentation

virtual Msg* singa::Server::HandleGet ( Msg ** msg )

protectedvirtual

Process GET request.

Returns: the orignal message or a response message which contains the values of the Param with the request version.

virtual Msg* singa::Server::HandlePut ( Msg ** msg )

protectedvirtual

Process PUT request.

Returns: the original message or response message. If we don't want to acknowledge the put request, then return nullptr.

virtual Msg* singa::Server::HandleSyncRequest ( Msg ** msg )

protectedvirtual

Handle sync request from other server groups.

It adds updates of Param (slice) from other server groups directly to local Param (slice). Currently, each Param (slice) has a master group, i.e., slice2group_[sliceid], which would receive such requests from all other server groups for the Param object.

Parameters

msg	request msg containing the parameter updates

Returns: response msg that contains the fresh parameter values.

void singa::Server::HandleSyncResponse ( Msg ** msg )

protected

Handle sync response.

The response msg includes the latest values of a Param object, for which this server sent the sync request to the master/maintainer group. The local Param values are replaced with the addition result of local udpates since the sync request was sent and the received Param values.

Parameters

response message

const std::vector<Msg*> singa::Server::HandleUpdate ( Msg ** msg )

protected

Process Update request.

It waits until received the gradients from all workers from the same worker group. After updating, it responses to each sender with the new Param values. It may generate a sync message to the server group that maintains the global version of the updated Param (slice).

Note: there is no counter for each worker group on the number of received update requests. Hence it is possible that the server would conduct the update when it receives x requests from group a and y requests from group b where x + y = group size. To avoid this problem, we can

maintain request list for each group for each Param at the server side
do not span a worker group among multiple nodes. then the updates from the same group would be locally aggregated on the worker node. And the server would conduct the update immediately after receiving the aggregated request.
launch only one worker group.

Returns: the orignal message or response message

The documentation for this class was generated from the following file:

/home/wangwei/program/asf/release-0.1/apache-singa-incubating-0.1.0-RC1/include/trainer/server.h

Public Member Functions

Protected Member Functions

Protected Attributes

Member Function Documentation