Reading Map Metrics

By default, you can read metrics for a given map, such as the primary and backup entry count, last update time, and locked entry count on each member of your cluster. You can access these statistics for the entire map, for the map entries on a specific cluster member, or specific map entries.

Getting Statistics about All Map Entries

To get statistics for all map entries that are owned by a member, use the getLocalMapStats() method of the Java member API (embedded mode). This method returns data only if the statistics-enabled element is set to true, which is the default.

note

If you disable map statistics, statistics will not be available via the API, or in Hazelcast Management Center.

XML

xml

<hazelcast>
    ...
    <map name="myMap">
        <statistics-enabled>true</statistics-enabled>
    </map>
    ...
</hazelcast>

YAML

yaml

hazelcast:
  map:
    myMap:
      statistics-enabled: true

java

LocalMapStats mapStatistics = myMap.getLocalMapStats();
System.out.println( "Number of entries owned by this member = "
    + mapStatistics.getOwnedEntryCount() );

note

If you need cluster-wide map statistics, you can get the local map statistics from all members of the cluster and combine them. Alternatively, you can see all map statistics in Hazelcast Management Center.

Getting Statistics about a Specific Map Entry

To get statistics for a specific map entry, you can use the getEntryView(key) method of one of the following available client libraries. To use this method, the map must have its per-entry-stats-enabled element set to true.

This method returns the following statistics:

Statistic	Description
cost	Cost (in bytes) of the entry.
creationTime	Creation time of the entry.
expirationTime	Expiration time of the entry.
hits	Number of hits of the entry.
key	Key of the entry.
lastAccessTime	Last access time for the entry.
lastStoredTime	Last time the value was saved to a MapStore.
lastUpdateTime	Last time the value was updated.
maxIdle	Last set max idle time in milliseconds.
ttl	Last set time-to-live in milliseconds.
value	Value of the entry.
version	Version of the entry.

XML

xml

<hazelcast>
    ...
    <map name="myMap">
        <per-entry-stats-enabled>true</per-entry-stats-enabled>
    </map>
    ...
</hazelcast>

YAML

yaml

hazelcast:
  map:
    myMap:
      per-entry-stats-enabled: true

Java (Embedded Mode)

java

HazelcastInstance hz = Hazelcast.newHazelcastInstance();

EntryView entry = hz.getMap( "quotes" ).getEntryView( "key" );

System.out.println ( "size in memory  : " + entry.getCost() );
System.out.println ( "creationTime    : " + entry.getCreationTime() );
System.out.println ( "expirationTime  : " + entry.getExpirationTime() );
System.out.println ( "number of hits  : " + entry.getHits() );
System.out.println ( "lastAccessedTime: " + entry.getLastAccessTime() );
System.out.println ( "lastUpdateTime  : " + entry.getLastUpdateTime() );
System.out.println ( "version         : " + entry.getVersion() );
System.out.println ( "key             : " + entry.getKey() );
System.out.println ( "value           : " + entry.getValue() );

Java (Client/Server Mode)

java

HazelcastInstance hz = HazelcastClient.newHazelcastClient();

EntryView entry = hz.getMap( "map" ).getEntryView( "key" );

System.out.println ( "size in memory  : " + entry.getCost() );
System.out.println ( "creationTime    : " + entry.getCreationTime() );
System.out.println ( "expirationTime  : " + entry.getExpirationTime() );
System.out.println ( "number of hits  : " + entry.getHits() );
System.out.println ( "lastAccessedTime: " + entry.getLastAccessTime() );
System.out.println ( "lastUpdateTime  : " + entry.getLastUpdateTime() );
System.out.println ( "version         : " + entry.getVersion() );
System.out.println ( "key             : " + entry.getKey() );
System.out.println ( "value           : " + entry.getValue() );

C++

cpp

auto hz = hazelcast::new_client().get();
auto map = hz.get_map( "map" ).get();
auto entry = map->get_entry_view<std::string, std::string>("key").get();
std::cout << "size in memory  : " << entry->cost << std::endl;
std::cout << "creationTime    : " << entry->creation_time << std::endl;
std::cout << "expirationTime  : " << entry->expiration_time << std::endl;
std::cout << "number of hits  : " << entry->hits << std::endl;
std::cout << "lastAccessedTime: " << entry->last_access_time << std::endl;
std::cout << "lastUpdateTime  : " << entry->last_update_time << std::endl;
std::cout << "version         : " << entry->version << std::endl;
std::cout << "key             : " << entry->key << std::endl;
std::cout << "value           : " << entry->value << std::endl;

C Sharp

cs

await using var client = await HazelcastClientFactory.StartNewClientAsync();
await using var map = await client.GetMapAsync<string, string>("map");
var entry = await map.GetEntryViewAsync("key");

Console.WriteLine($"Size in memory  : {entry.Cost}");
Console.WriteLine($"Creation time   : {entry.CreationTime}");
Console.WriteLine($"Expiration time : {entry.ExpirationTime}");
Console.WriteLine($"Number of hits  : {entry.Hits}");
Console.WriteLine($"Last access time: {entry.LastAccessTime}");
Console.WriteLine($"Last update time: {entry.LastUpdateTime}");
Console.WriteLine($"Last update time: {entry.LastUpdateTime}");
Console.WriteLine($"Version         : {entry.Version}");
Console.WriteLine($"Key             : {entry.Key}");
Console.WriteLine($"Value           : {entry.Value}");

Node.js

javascript

const client = await Client.newHazelcastClient();
const map = await client.getMap('map');
const entryView = await map.getEntryView('key');
console.log(`size in memory  :  ${entry.cost}`);
console.log(`creationTime    : ${entry.creationTime}`);
console.log(`expirationTime  : ${entry.expirationTime}`);
console.log(`number of hits  : ${entry.hits}`);
console.log(`lastAccessedTime: ${entry.lastAccessTime}`);
console.log(`lastUpdateTime  : ${entry.lastUpdateTime}`);
console.log(`version         : ${entry.version}`);
console.log(`key             : ${entry.key}`);
console.log(`value           : ${entry.value}`);

Python

python

client = hazelcast.HazelcastClient()
entry = client.get_map("map").get_entry_view("key").result()
print("size in memory  :", entry.cost)
print("creationTime    :", entry.creation_time)
print("expirationTime  :", entry.expiration_time)
print("number of hits  :", entry.hits)
print("lastAccessedTime:", entry.last_access_time)
print("lastUpdateTime  :", entry.last_update_time)
print("version         :", entry.version)
print("key             :", entry.key)
print("value           :", entry.value)

Go

go

// error handling is omitted for brevity
hzclient, _ := hazelcast.StartNewClient()
ctx := context.TODO()
myMap, _ := hz.GetMap(ctx, "my-map")
entry, _ := myMap.GetEntryView(ctx, "key")
fmt.Println("Size in memory     :", entry.Cost)
fmt.Println("Creation time      :", entry.CreationTime)
fmt.Println("Expiration time    :", entry.ExpirationTime)
fmt.Println("Number of hits     :", entry.Hits)
fmt.Println("Last accessed time :", entry.LastAccessTime)
fmt.Println("Last updated time  :", entry.LastUpdateTime)
fmt.Println("Version            :", entry.Version)
fmt.Println("Key                :", entry.Key)
fmt.Println("Value              :", entry.Value)