// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
fmt.Println("New an libstore")
client, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
// log.Fatalln("dialing:", err)
return nil, errors.New("meet error when DialHTTP")
}
args := &storagerpc.GetServersArgs{}
reply := &storagerpc.GetServersReply{}
num := 0
for reply.Status != storagerpc.OK {
if num >= 5 {
return nil, errors.New("cannot find the storage server")
}
err = client.Call("StorageServer.GetServers", args, reply)
if err != nil {
return nil, errors.New("meet error when client call")
}
if reply.Status != storagerpc.OK {
time.Sleep(1000 * time.Millisecond)
}
num++
}
libstore := &libstore{
Servers: reply.Servers,
// keyValueMutex: make(map[string]*sync.Mutex),
// keyListMutex: make(map[string]*sync.Mutex),
mutex: &sync.Mutex{},
// client: client,
keyValue: make(map[string]*valuelib),
keylist: make(map[string]*listlib),
keyValudhistory: make(map[string]*list.List),
keyListhistory: make(map[string]*list.List),
keyValueMutex: make(map[string]*sync.Mutex),
keyListMutex: make(map[string]*sync.Mutex),
mode: mode,
clientmap: make(map[string]*rpc.Client),
myHostPort: myHostPort,
}
libstore.clientmap[masterServerHostPort] = client
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
// retry until register sucessfully
for err != nil {
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
}
go libstore.epochtime()
return libstore, nil
// return nil, errors.New("not implemented")
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
client, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, errors.New("Error DialHTTP in NewLibstore")
}
args := &storagerpc.GetServersArgs{}
reply := &storagerpc.GetServersReply{}
storageReady := false
for i := 0; i < 5; i++ {
err = client.Call("StorageServer.GetServers", args, reply)
if err != nil {
return nil, errors.New("Error Call in NewLibstore")
}
if reply.Status == storagerpc.OK {
storageReady = true
break
} else {
time.Sleep(1 * time.Second)
}
}
if storageReady == false {
return nil, errors.New("Storage not ready after 5 trial in NewLibstore")
}
ls := &libstore{
StorageServers: reply.Servers,
connectionMap: make(map[string]*rpc.Client),
HostPort: myHostPort,
CacheValueSet: make(map[string]*valueCache),
CacheListSet: make(map[string]*listCache),
queryGetQueue: make(map[string]*list.List),
queryListQueue: make(map[string]*list.List),
queryGetMutex: make(map[string]*sync.Mutex),
queryListMutex: make(map[string]*sync.Mutex),
mutex: &sync.Mutex{},
mode: mode,
}
ls.connectionMap[masterServerHostPort] = client
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(ls))
for err != nil {
fmt.Println("Error LeaseCallbacks in NewLibstore")
// return nil, errors.New("Error LeaseCallbacks in NewLibstore")
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(ls))
}
go func() {
for {
select {
case <-time.After(time.Duration(storagerpc.LeaseSeconds/2) * time.Second):
ls.updateCache()
case <-time.After(time.Duration(storagerpc.QueryCacheSeconds/2) * time.Second):
ls.updateQueue()
}
}
}()
return ls, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
master_server, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, errors.New("Cannot connect to the master server")
}
// Call GetServers to get storage servers' information
var args storagerpc.GetServersArgs
var reply storagerpc.GetServersReply
master_server.Call("StorageServer.GetServers", args, &reply)
if reply.Status == storagerpc.NotReady {
for i := 0; i < 5; i++ {
time.Sleep(1 * time.Second)
master_server.Call("StorageServer.GetServers", args, &reply)
if reply.Status == storagerpc.OK {
break
}
}
}
master_server.Close()
if reply.Status == storagerpc.NotReady {
return nil, errors.New("Storage Server is not ready yet")
}
// Register RPC connection for each storage server
ls := &libstore{}
// Sort the servers by NodeID
sort.Sort(SortNodeByNodeID(reply.Servers))
ls.servers = reply.Servers
ls.rpc_connection = make([]*rpc.Client, len(ls.servers))
ls.host_port = myHostPort
ls.lease_mode = mode
ls.query_record = make(map[string]*list.List)
ls.value_cache = make(map[string]*ValueCacheElement)
ls.list_cache = make(map[string]*ListCacheElement)
ls.query_record_locker = new(sync.Mutex)
ls.value_cache_locker = new(sync.Mutex)
ls.list_cache_locker = new(sync.Mutex)
go ls.CacheCleaner()
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(ls))
if err != nil {
return nil, errors.New("Could not register Libstore")
}
for i, server := range ls.servers {
ls.rpc_connection[i], _ = rpc.DialHTTP("tcp", server.HostPort)
}
return ls, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
master, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
args := &storagerpc.GetServersArgs{}
var reply storagerpc.GetServersReply
for i := 0; i < 5; i++ {
master.Call("StorageServer.GetServers", args, &reply)
if reply.Status == storagerpc.OK {
break
} else {
time.Sleep(time.Second)
}
}
if reply.Status != storagerpc.OK {
return nil, nil // After retry for 5 times...
}
nodeList := nodes(reply.Servers)
sort.Sort(nodeList)
nodeListSorted := ([]storagerpc.Node)(nodeList)
newLib := &libstore{
master: master,
svrMap: make(map[uint32]*rpc.Client),
myHostPort: myHostPort,
allServerNodes: nodeListSorted,
svrMutex: &sync.Mutex{},
counter: make(map[string]int),
counterMutex: &sync.Mutex{},
sMutex: &sync.Mutex{},
sCache: make(map[string]*sCachNode),
lMutex: &sync.Mutex{},
lCache: make(map[string]*lCachNode),
mode: mode,
}
if mode != Never {
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(newLib))
}
go newLib.selfRevoke()
go newLib.selfCleanCounter()
return newLib, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
ls := &libstore{
myHostPort: myHostPort,
mode: mode,
storageServers: make(map[uint32]*storagerpc.Node),
cache: newCache(),
storageRPCHandler: make(map[uint32]*rpc.Client),
accessInfoHub: newAccessInfoHub(),
}
// connect to the master server and get the server list
master, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
var args storagerpc.GetServersArgs
var reply storagerpc.GetServersReply
ok := false
for i := 0; i < maximumTrials; i++ {
err = master.Call("StorageServer.GetServers", &args, &reply)
if reply.Status == storagerpc.OK {
ok = true
break
}
time.Sleep(time.Second)
}
if !ok {
return nil, errors.New("Cannot get servers after " + strconv.Itoa(maximumTrials) + " trials")
}
// adding the server list
for _, s := range reply.Servers {
ls.storageServers[s.NodeID] = &s
ls.storageRPCHandler[s.NodeID], err = rpc.DialHTTP("tcp", s.HostPort)
if err != nil {
return nil, err
}
}
// register the callback
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(ls))
go ls.gc()
return ls, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
cli, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
args := &storagerpc.GetServersArgs{}
var reply storagerpc.GetServersReply
for i := 0; i < 6; i++ {
if err := cli.Call("StorageServer.GetServers", args, &reply); err != nil {
return nil, err
}
if reply.Status != storagerpc.NotReady {
break
}
time.Sleep(time.Duration(1) * time.Second)
}
if reply.Status != storagerpc.OK {
return nil, errors.New("GetServers f****d up mane")
}
clients := make(map[uint32]*rpc.Client)
for _, node := range reply.Servers {
cli, err := rpc.DialHTTP("tcp", node.HostPort)
if err != nil {
return nil, err
}
clients[node.NodeID] = cli
}
libstore := createLibStore(clients, mode)
go libstore.epochloop()
go libstore.eventHandler()
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
return libstore, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
//fmt.Println("begin connection")
cli, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
defer cli.Close()
var args storagerpc.GetServersArgs
var reply storagerpc.GetServersReply
for i := 0; i < 5; i++ {
err = cli.Call("StorageServer.GetServers", &args, &reply)
if err != nil {
fmt.Println("no such methods")
return nil, err
}
if reply.Status == storagerpc.OK {
//fmt.Println("connection succeed!")
break
}
time.Sleep(1000 * time.Millisecond)
}
if reply.Status == storagerpc.NotReady || reply.Servers == nil {
return nil, errors.New("storage server haven't ready")
}
lib := new(libstore)
lib.hostport = myHostPort
lib.mode = mode
lib.nodes = reply.Servers
lib.rpcClient = make([]*rpc.Client, len(lib.nodes))
lib.leases = cache.NewCache()
// DO WEEE NEED TO SORT???
//fmt.Println("connection succeed!")
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(lib))
go CleanCache(lib.leases)
return lib, nil
}
func initStorageTester(server, myhostport string) (*storageTester, error) {
tester := new(storageTester)
tester.myhostport = myhostport
tester.recvRevoke = make(map[string]bool)
tester.compRevoke = make(map[string]bool)
// Create RPC connection to storage server.
srv, err := rpc.DialHTTP("tcp", server)
if err != nil {
return nil, fmt.Errorf("could not connect to server %s", server)
}
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(tester))
rpc.HandleHTTP()
l, err := net.Listen("tcp", fmt.Sprintf(":%d", *portnum))
if err != nil {
LOGE.Fatalln("Failed to listen:", err)
}
go http.Serve(l, nil)
tester.srv = srv
return tester, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when localCache are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle localCache. If mode is Never, then the Libstore should never request
// localCache from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// localCache from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
cli, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
defer cli.Close()
var args storagerpc.GetServersArgs
var reply storagerpc.GetServersReply
for i := 0; i < 5; i++ {
err = cli.Call("StorageServer.GetServers", &args, &reply)
if err != nil {
return nil, err
}
if reply.Status == storagerpc.OK {
break
}
time.Sleep(1000 * time.Millisecond)
}
if reply.Status == storagerpc.NotReady {
return nil, errors.New("storage server haven't ready")
}
lib := new(libstore)
lib.hostport = myHostPort
lib.mode = mode
sort.Sort(storagerpc.NodeSlice(reply.Servers))
lib.nodes = reply.Servers
lib.rpcClientIndex = make(map[uint32]*rpc.Client)
lib.localCache = libcache.NewCache()
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(lib))
return lib, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
if myHostPort == "" && mode != Never {
fmt.Println("@@@@FatalBughhh")
}
cli, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
// keep retrying for at most 5 times.
args := &storagerpc.GetServersArgs{}
var storages []storageNode
for i := 0; ; i++ {
var reply storagerpc.GetServersReply
if cli.Call("StorageServer.GetServers", args, &reply) != nil {
fmt.Println("@@@@FatalError: libstore RPC function call failed. -> GetServers!")
}
if reply.Status == storagerpc.OK {
storages = make([]storageNode, len(reply.Servers), len(reply.Servers))
err = WrapNode(reply.Servers, storages)
// fmt.Println("After the wrapping:", storages)
if err != nil {
return nil, err
}
break
}
fmt.Println("LibStore retrying connection...", i)
time.Sleep(time.Second)
if i == 6 {
fmt.Println("@@@@FatalError: libstore has tried 5 times, but the master node is still not ready!")
return nil, err
}
}
dCache := make(map[string](*dataUnit))
qCache := make(map[string]([]int64))
lib := &libstore{
storages: storages,
callback: myHostPort,
mode: mode,
dataCache: dCache,
queryCache: qCache}
// register call back if needed
if mode != Never {
if err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(lib)); err != nil {
fmt.Println("@@@@Fatal Error, cannot register the libstore's RPC", err)
return nil, err
}
}
go lib.GarbageCollection()
fmt.Println("Libstore created:", lib.callback)
return lib, nil
}
// NewLibstore creates a new instance of a TribServer's libstore. masterServerHostPort
// is the master storage server's host:port. myHostPort is this Libstore's host:port
// (i.e. the callback address that the storage servers should use to send back
// notifications when leases are revoked).
//
// The mode argument is a debugging flag that determines how the Libstore should
// request/handle leases. If mode is Never, then the Libstore should never request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to false). If mode is Always, then the Libstore should always request
// leases from the storage server (i.e. the GetArgs.WantLease field should always
// be set to true). If mode is Normal, then the Libstore should make its own
// decisions on whether or not a lease should be requested from the storage server,
// based on the requirements specified in the project PDF handout. Note that the
// value of the mode flag may also determine whether or not the Libstore should
// register to receive RPCs from the storage servers.
//
// To register the Libstore to receive RPCs from the storage servers, the following
// line of code should suffice:
//
// rpc.RegisterName("LeaseCallbacks", librpc.Wrap(libstore))
//
// Note that unlike in the NewTribServer and NewStorageServer functions, there is no
// need to create a brand new HTTP handler to serve the requests (the Libstore may
// simply reuse the TribServer's HTTP handler since the two run in the same process).
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
ls := new(libstore)
rpc.RegisterName("LeaseCallbacks", librpc.Wrap(ls))
var client *rpc.Client
var err error
// Connect to master storage server
for try := 1; try <= 5; try++ {
client, err = rpc.DialHTTP("tcp", masterServerHostPort)
if err == nil {
break
}
if try == 5 {
return nil, err
}
time.Sleep(time.Second)
}
var args storagerpc.GetServersArgs
var reply storagerpc.GetServersReply
var servers []storagerpc.Node
// Try five times to request the list of storage servers from the master
for i := 1; i <= 5; i++ {
client.Call("StorageServer.GetServers", args, &reply)
if reply.Status == storagerpc.OK {
// Success! Store list of servers
servers = reply.Servers
break
} else {
// Failure, sleep one second and try again
if i == 5 {
return nil, errors.New("Couldn't connect to storage server")
}
time.Sleep(time.Second)
}
}
// Create libstore and save the connection to the master server
var clients = make([]*rpc.Client, len(reply.Servers))
// WRONG! StorageServer does not assume servers[0] is master
//clients[0] = client
for j := 0; j < len(servers); j++ {
if servers[j].HostPort == masterServerHostPort {
clients[j] = client
break
}
}
ls.myHostPort = myHostPort
ls.mode = mode
ls.servers = servers
ls.clients = clients
ls.cacheGet = make(map[string]string) // maps key to result
ls.cacheValid = make(map[string]bool)
ls.cacheList = make(map[string][]string)
ls.cacheTimes = make(map[string][]time.Time)
ls.cacheRecent = make(map[string]int)
return ls, nil
// So it won't yell at me for fmt
fmt.Println(1)
return nil, nil
}
func NewLibstore(masterServerHostPort, myHostPort string, mode LeaseMode) (Libstore, error) {
fmt.Println("Starting NewLibstore-")
masterServ, err := rpc.DialHTTP("tcp", masterServerHostPort)
if err != nil {
return nil, err
}
getServArgs := storagerpc.GetServersArgs{}
//declare empty struct to store return
var getServReply storagerpc.GetServersReply
//retry every second, if not yet ready
//timer := time.NewTimer(time.Second * 1)
var tryCount int = 0
Loop:
for {
//fmt.Println("calling get servers")
err = masterServ.Call("StorageServer.GetServers", getServArgs, &getServReply)
//fmt.Println("Return from rpc call")
if err != nil {
return nil, err
} else {
//err is nil
if getServReply.Status == storagerpc.OK {
//fmt.Println("NewLibstore: Status OK, breaking..")
break Loop
}
}
if tryCount == 4 {
return nil, errors.New(TIMEOUT_GETTING_SERVERS)
}
//status is not OK; wait for timer
//fmt.Println("Waiting for timer channel..")
time.Sleep(1 * time.Second)
//fmt.Println("Slowserv: counting ", tryCount)
tryCount++
}
//Convert to sort interface type and sort
var toBeSortedNodes NodeByID = NodeByID(getServReply.Servers)
sort.Sort(toBeSortedNodes)
//Convert back to []Node type
var sortedNodes []storagerpc.Node = []storagerpc.Node(toBeSortedNodes)
fmt.Println(sortedNodes)
//initialise server-connection map
serverConnMap := make(map[storagerpc.Node]*rpc.Client)
//initialise connection with all nodes
for _, node := range sortedNodes {
serverConn, err := rpc.DialHTTP("tcp", node.HostPort)
if err != nil {
fmt.Println("Error DialHTTP in libstore with a node")
} else {
//add to cache
serverConnMap[node] = serverConn
}
}
//TODo add master server to map?
var newLs libstore = libstore{
masterServ: masterServ,
allServerNodes: sortedNodes,
serverConnMap: serverConnMap,
dataMap: make(map[string]interface{}),
dataMapLock: &sync.Mutex{},
queries: make(map[string]([]time.Time)),
queriesLock: &sync.Mutex{},
leases: make(map[leaseinfo]bool),
leasesLock: &sync.Mutex{},
mode: mode,
hostPort: myHostPort,
}
err = rpc.RegisterName("LeaseCallbacks", librpc.Wrap(&newLs))
if err != nil {
fmt.Println(err)
return nil, err
}
go newLs.evictFromCache() //run in background
return &newLs, nil
}