6.6.8.1.1.1. Quasardb

public final class Quasardb implements Iterable<QuasardbEntry<?>>

Quasardb main abstraction layer. The following operations are allowed:

  • get: get an entry.
  • next: get the next entry in the iteration
  • hasNext: is there a next entry in the iteration ?
  • put: create an entry.
  • update: update the value of an existing entry.
  • getAndReplace: atomically update the value of an existing entry and return the old value.
  • compareAndSwap: atomically compare a value with comparand and update if it matches. Always return the old value.
  • remove: delete an entry.
  • removeAll: delete all entries. Use with caution.
  • removeIf: delete the object associated whith a key if the object is equal to comparand.
  • getRemove: atomically get the entry associated with the supplied key and remove it.
  • close: close the connection.
  • getVersion: get API version.
  • getBuild: get API build number.
  • getCurrentNodeConfig: retrieve the configuration of the current quasardb instance.
  • getNodeConfig: retrieve the configuration of the given quasardb instance.
  • getCurrentNodeStatus: retrieve the status of the current quasardb instance.
  • getNodeStatus: retrieve the status of the given quasardb instance.
  • getCurrentNodeTopology: retrieve the topology of the current quasardb instance.
  • getNodeTopology: retrieve the topology of the given quasardb instance.
  • runBatch: can increase performance when it is necessary to run many small operations.
  • stopCurrentNode: stop the current quasardb instance.
  • stopNode: stop a provided quasardb instance.
  • purgeAll: remove all entries of quasardb cluster in one operation.
  • startsWith: perform a search prefix based operation on all quasardb entries.
  • set/getExpiryTimeInSeconds: set or retrieve expiry time in seconds for a provided alias.
  • set/getExpiryTimeInDate: set or retrieve expiry time in java.util.Date for a provided alias.

Usage example :

// First : create a configuration object.
QuasardbConfig config = new QuasardbConfig();

// Second : create a node object
QuasardbNode node = new QuasardbNode("127.0.0.1", 1234);

// Third : add new node to config
config.addNode(node);

// Fourth : create a related quasardb instance.
Quasardb qdb = new Quasardb(config);
// Or you can supply the configuration later :
//   Quasardb qdb = new Quasardb();
//   qdb.setConfig(config);

// Fifth : connect to quasardb cluster.
qdb.connect();

// Sixth : use the quasardb instance :
qdb.put("foo", new String("bar"));
System.out.println("  => key 'foo' contains : " + qdb.get("foo"));

// Seventh : disconnect from the quasardb cluster
// Notice that this step is optional
qdb.close();

Note about entries :

  • You cannot create or access entries starting with “qdb”.
  • A majority of entries type can be stored in quasardb without any further work. But there are some limitations. As Kryo is the underlying framework used to serialize objects in quasardb, you can find all limitations by consulting kryo’s documentation (https://github.com/EsotericSoftware/kryo#compatibility)
Author:© quasardb - 2014

6.6.8.1.1.1.1. Constructors

6.6.8.1.1.1.1.1. Quasardb

public Quasardb()

6.6.8.1.1.1.1.2. Quasardb

public Quasardb(QuasardbConfig config)

Create a quasardb instance with the provided configuration. The configuration must have the following parameters :

  • nodes: a collection of QuasardbNode.
  • expiry: the default expiry time in seconds for all new entries.

Example :

// First : create a configuration.
QuasardbConfig config = new QuasardbConfig();

// Second : add a node to the configuration
QuasardbNode node = new QuasardbNode("127.0.0.1", 2836);
config.addNode(node);

// Optionnaly set a default expiry time in seconds on all next entries
config.setExpiryTimeInSeconds(2);

// Second : create a related quasardb instance.
Quasardb myQuasardbInstance = new Quasardb(config);
Parameters:
  • config – the config map in order to initialize connexion with the quasardb instance
Throws:
  • QuasardbException – if initialization step fail

6.6.8.1.1.1.2. Methods

6.6.8.1.1.1.2.1. close

public void close()

Close the connection to the quasardb instance and frees resources.

Throws:

6.6.8.1.1.1.2.2. compareAndSwap

public <V> V compareAndSwap(String alias, V value, V comparand)

Atomically compare an existing alias with comparand, updates it to new if they match and return the original value. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster
  • value – the new object to associate to the key
  • comparand – the object to compare with original value associated to the key
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

the original value associated to the key

6.6.8.1.1.1.2.3. compareAndSwap

public <V> V compareAndSwap(String alias, V value, V comparand, long expiryTime)

Atomically compare an existing alias with comparand, updates it to new if they match and return the original value. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster
  • value – the new object to associate to the key
  • comparand – the object to compare with original value associated to the key
  • expiryTime – expiry time in seconds associate to the key. The provided value is prior to the default expiry time.
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

the original value associated to the key

6.6.8.1.1.1.2.4. connect

public void connect()

Initialize connection to the quasardb instance and setup serialization framework.

Throws:

6.6.8.1.1.1.2.5. get

public <V> V get(String alias)

Get the entry associated with the supplied unique key (alias). Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – the object’s unique key/alias.
Throws:
  • QuasardbException – if an error occurs, the entry does not exist or the entry starts with “qdb”.
Returns:

the object’s related to the alias

6.6.8.1.1.1.2.6. getAndReplace

public <V> V getAndReplace(String alias, V value)

Update an existing alias with data and return its previous value. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster
  • value – the new object to associate to the key
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

the previous value associated to the key

6.6.8.1.1.1.2.7. getAndReplace

public <V> V getAndReplace(String alias, V value, long expiryTime)

Update an existing alias with data and return its previous value. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster
  • value – the new object to associate to the key
  • expiryTime – expiry time in seconds associate to the key. The provided value is prior to the default expiry time.
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

the previous value associated to the key

6.6.8.1.1.1.2.8. getBuild

public String getBuild()

Retrieve the build version of the current quasardb instance.

Throws:
Returns:

build version of the current quasardb instance.

6.6.8.1.1.1.2.9. getConfig

public final QuasardbConfig getConfig()

Get the current instance configuration.

Throws:
Returns:

current quasardb configuration

See also: QuasardbConfig

6.6.8.1.1.1.2.10. getCurrentNodeConfig

public String getCurrentNodeConfig()

Retrieve the configuration of the current quasardb instance in JSON. JSON response has the following format :

{
      "global":{
          "depot":{
              "replication_factor":1,
              "root":"db",
              "sync":false,
              "transient":false
          },
          "limiter":{
              "max_bytes":12883636224,
              "max_in_entries_count":100000
          }
      },
      "local":{
          "chord":{
              "bootstrapping_peers":[],
              "no_stabilization":false,
              "node_id":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
          },
          "logger":{
              "dump_file":"qdb_error_dump.txt",
              "flush_interval":3,
              "log_files":[],
              "log_level":2,
              "log_to_console":true,
              "log_to_syslog":false
          },
          "network":{
              "client_timeout":60,
              "idle_timeout":300,
              "listen_on":"127.0.0.1:2836",
              "partitions_count":5,
              "server_sessions":2000
          },
          "user":{
              "license_file":"qdb.lic"
          }
      }
}
Throws:
Returns:

configuration of the current quasardb instance.

6.6.8.1.1.1.2.11. getCurrentNodeStatus

public String getCurrentNodeStatus()

Retrieve the status of the current quasardb instance in JSON format. JSON response has the following format :

{
      "engine_build_date":"87f8d02 2014-01-15 16:12:30 +0100",
      "engine_version":"master",
      "entries":
      {
         "persisted":{"count":0,"size":0},
          "resident":{"count":0,"size":0}
      },
      "hardware_concurrency":6,
      "memory":
      {
          "physmem":{"total":25767272448,"used":5493329920},
          "vm":{"total":8796092891136,"used":417980416}
      },
      "network":{
          "listening_address":"127.0.0.1",
          "listening_port":2836,
          "partitions":
          {
              "available_sessions":[1999,1999,2000,2000,2000],
              "count":5,
              "max_sessions":2000
          }
      },
      "node_id":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9",
      "operating_system":"Microsoft Windows 7 Ultimate Edition Service Pack 1 (build 7601), 64-bit",
      "operations":
      {
          "compare_and_swap":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find_remove":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find_update":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "put":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "remove":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "purge_all":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
         },
          "remove_if":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "update":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
         }
      },
      "overall":{
          "count":0,
          "evictions":0,
          "failures":0,
          "in_bytes":0,
          "out_bytes":0,
          "pageins":0,
          "successes":0
      },
      "startup":"2014-01-20T15:01:11",
      "timestamp":"2014-01-20T15:09:40"
}
Throws:
Returns:

status of the current quasardb instance in JSON

6.6.8.1.1.1.2.12. getCurrentNodeTopology

public String getCurrentNodeTopology()

Retrieve the topology of the current quasardb instance in JSON. JSON response has the following format :

{
      "center":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      },
      "predecessor":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      },
      "successor":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      }
}
Throws:
Returns:

topology of the current quasardb instance.

6.6.8.1.1.1.2.13. getDefaultExpiryTimeInSeconds

public long getDefaultExpiryTimeInSeconds()

Get the default expiry time in seconds for all new entries. Return the 0 value if entries are eternal

Returns:0 if entries are eternal, a value in seconds instead.

6.6.8.1.1.1.2.14. getExpiryTimeInDate

public Date getExpiryTimeInDate(String alias)

Retrieve the expiry time in date for a provided alias

Parameters:
  • alias – the object’s unique key/alias.
Throws:
  • QuasardbException – if the connection with current instance fail or provided alias doesn’t exist or prodived alias is reserved.
Returns:

the expiry date related to the provided alias.

6.6.8.1.1.1.2.15. getExpiryTimeInSeconds

public long getExpiryTimeInSeconds(String alias)

Retrieve the expiry time in seconds for a provided alias

Parameters:
  • alias – the object’s unique key/alias.
Throws:
  • QuasardbException – if the connection with current instance fail or provided alias doesn’t exist or prodived alias is reserved.
Returns:

the expiry time in second related to the provided alias. 0 means eternal duration.

6.6.8.1.1.1.2.16. getNodeConfig

public String getNodeConfig(String node, int port)

Retrieve the configuration of the specific quasardb instance in JSON. JSON response has the following format :

{
      "global":{
          "depot":{
              "replication_factor":1,
              "root":"db",
              "sync":false,
              "transient":false
          },
          "limiter":{
              "max_bytes":12883636224,
              "max_in_entries_count":100000
          }
      },
      "local":{
          "chord":{
              "bootstrapping_peers":[],
              "no_stabilization":false,
              "node_id":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
          },
          "logger":{
              "dump_file":"qdb_error_dump.txt",
              "flush_interval":3,
              "log_files":[],
              "log_level":2,
              "log_to_console":true,
              "log_to_syslog":false
          },
          "network":{
              "client_timeout":60,
              "idle_timeout":300,
              "listen_on":"127.0.0.1:2836",
              "partitions_count":5,
              "server_sessions":2000
          },
          "user":{
              "license_file":"qdb.lic"
          }
      }
}
Parameters:
  • node – the host of the quasardb node you want to retrieve configuration
  • port – the port of the quasardb node you want to retrieve configuration
Throws:
Returns:

configuration of the current quasardb instance.

6.6.8.1.1.1.2.17. getNodeStatus

public String getNodeStatus(String node, int port)

Retrieve the status of the current quasardb instance in JSON format. JSON response has the following format :

{
      "engine_build_date":"87f8d02 2014-01-15 16:12:30 +0100",
      "engine_version":"master",
      "entries":
      {
         "persisted":{"count":0,"size":0},
          "resident":{"count":0,"size":0}
      },
      "hardware_concurrency":6,
      "memory":
      {
          "physmem":{"total":25767272448,"used":5493329920},
          "vm":{"total":8796092891136,
          "used":417980416}
      },
      "network":{
          "listening_address":"127.0.0.1",
          "listening_port":2836,
          "partitions":
          {
              "available_sessions":[1999,1999,2000,2000,2000],
              "count":5,
              "max_sessions":2000
          }
      },
      "node_id":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9",
      "operating_system":"Microsoft Windows 7 Ultimate Edition Service Pack 1 (build 7601), 64-bit",
      "operations":
      {
          "compare_and_swap":{
              "count":0,
              "evictions":0,
              "failures":0,
             "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find_remove":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "find_update":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "put":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "remove":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "purge_all":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
         },
          "remove_if":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
          },
          "update":{
              "count":0,
              "evictions":0,
              "failures":0,
              "in_bytes":0,
              "out_bytes":0,
              "pageins":0,
              "successes":0
         }
      },
      "overall":{
          "count":0,
          "evictions":0,
          "failures":0,
          "in_bytes":0,
          "out_bytes":0,
          "pageins":0,
          "successes":0
      },
      "startup":"2014-01-20T15:01:11",
      "timestamp":"2014-01-20T15:09:40"
}
Parameters:
  • node – the host of the quasardb node you want to retrieve status
  • port – the port of the quasardb node you want to retrieve status
Throws:
Returns:

status of the current quasardb instance in JSON

6.6.8.1.1.1.2.18. getNodeTopology

public String getNodeTopology(String node, int port)

Retrieve the topology of the current quasardb instance. JSON response has the following format :

{
      "center":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      },
      "predecessor":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      },
      "successor":{
          "endpoint":"127.0.0.1:2836",
          "reference":"5309f39a3f176b9-179cd55bd9dc83e5-c09beea926e4bb75-a460c8c4e5487da9"
      }
}
Parameters:
  • node – the host of the quasardb node you want to retrieve topology
  • port – the port of the quasardb node you want to retrieve topology
Throws:
Returns:

topology of the current quasardb instance.

6.6.8.1.1.1.2.19. getRemove

public <V> V getRemove(String alias)

Atomically get the entry associated with the supplied unique key (alias) and remove it. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – the object’s unique key/alias.
Throws:
  • QuasardbException – if an error occurs, the entry does not exist or the entry starts with “qdb”.
Returns:

the object’s related to the alias

6.6.8.1.1.1.2.20. getVersion

public String getVersion()

Retrieve the version of the current quasardb instance.

Throws:
Returns:

version of the current quasardb instance.

6.6.8.1.1.1.2.21. iterator

public Iterator<QuasardbEntry<?>> iterator()

Quasardb implements Iterable for QuasardbEntry, providing support for simplified iteration. However iteration should be used with caution. It is an O(n) operation.

See also: java.lang.Iterable.iterator()

6.6.8.1.1.1.2.22. purgeAll

public void purgeAll()

Delete all the stored objects in the current quasardb instance. Use with caution

Throws:

6.6.8.1.1.1.2.23. put

public <V> void put(String alias, V value)

Adds an entry (value) to the current qdb instance under the alias key.

  • Entries must not already exist.
  • Entries starting with “qdb” are reserved.
Parameters:
  • alias – a key to uniquely identify the entry within the cluster.
  • value – object to associate to the key.
Throws:
  • QuasardbException – if an error occurs, the entry already exists or the entry starts with “qdb”.

6.6.8.1.1.1.2.24. put

public <V> void put(String alias, V value, long expiryTime)

Adds an entry (value) to the current qdb instance under the alias key.

  • Entries must not already exist.
  • Entries starting with “qdb” are reserved.
Parameters:
  • alias – a key to uniquely identify the entry within the cluster.
  • value – object to associate to the key.
  • expiryTime – expiry time in seconds associate to the key. The provided value is prior to the default expiry time.
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or the entry already exists or the entry is reserved (it starts with “qdb”).

6.6.8.1.1.1.2.25. remove

public boolean remove(String alias)

Delete the object associated with the alias key. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – the alias you want to delete.
Throws:
  • QuasardbException – if the connection with the current instance fail or provided alias is reserved (it starts with “qdb”).
Returns:

true if alias has been removed.

6.6.8.1.1.1.2.26. removeIf

public <V> boolean removeIf(String alias, V comparand)

Atomically delete the object associated whith the alias key if the object is equal to comparand. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – the alias you want to delete
  • comparand – the object you want to compare with
Throws:
  • QuasardbException – if the connection with the current instance fail or provided alias is reserved (it starts with “qdb”).
Returns:

true if provided alias has been removed

6.6.8.1.1.1.2.27. runBatch

public <V> Results runBatch(List<Operation<V>> operations)

Submit a list of operation which can increase performance when it is necessary to run many small operations. Using properly the batch operations requires :

  1. initializing
  2. running list of operations
  3. read results
Parameters:
  • operations – List of operations to submit in batch mode to Quasardb. See Operation
Returns:

All results of submitted operations in batch mode. See Results

6.6.8.1.1.1.2.28. setConfig

public void setConfig(QuasardbConfig config)

Updates the configuration properties

Parameters:
  • config – configuration properties
Throws:

See also: QuasardbConfig

6.6.8.1.1.1.2.29. setDefaultExpiryTimeInSeconds

public void setDefaultExpiryTimeInSeconds(long expiryTime)

Set the default expiry time in seconds for all next entries.

Parameters:
  • expiryTime – expiry time in seconds to set up
Throws:

6.6.8.1.1.1.2.30. setExpiryTimeAt

public void setExpiryTimeAt(String alias, Date expiryDate)

Change the expiry time for a provided alias at the provided date.

Parameters:
  • alias – the object’s unique key/alias.
  • expiryDate – the expiry date related to the provided alias.
Throws:
  • QuasardbException – if the connection with current instance fail, provided alias does not exist or is reserved

6.6.8.1.1.1.2.31. setExpiryTimeInSeconds

public void setExpiryTimeInSeconds(String alias, long expiryTime)

Change the expiry time in seconds for a provided alias

Parameters:
  • alias – the object’s unique key/alias.
  • expiryTime – the expiry time in second related to the provided alias (0 means eternal)
Throws:
  • QuasardbException – if the connection with current instance fail or provided alias doesn’t exist or a negative expiryTime is provided or prodived alias is reserved.

6.6.8.1.1.1.2.32. startsWith

public List<String> startsWith(String prefix)

Perform a search prefix based operation on all quasardb entries. Pay attention that :

  • search operation is based on aliases, not on values.
  • search operation is case sensitive.
  • searching on reserved aliases (starts with “qdb”) is not allowed.
Parameters:
  • prefix – prefix
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided prefix is reserved.
Returns:

all entries matching specified prefix

6.6.8.1.1.1.2.33. stopCurrentNode

public void stopCurrentNode(String reason)

Stop the current node with a given reason.

Parameters:
  • reason – the reason to stop the selected node.

6.6.8.1.1.1.2.34. stopNode

public void stopNode(String node, int port, String reason)

Stop a specific node with a given reason.

Parameters:
  • node – the host of the quasardb node you want to stop - can be a IP address or a hostname.
  • port – the port of the quasardb node you want to stop.
  • reason – the reason to stop the selected node.

6.6.8.1.1.1.2.35. toString

public String toString()

{@inheritDoc}

6.6.8.1.1.1.2.36. update

public <V> boolean update(String alias, V value)

Update an existing entry or create a new one. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster.
  • value – the new object to associate to the key
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

true if entry was updated

6.6.8.1.1.1.2.37. update

public <V> boolean update(String alias, V value, long expiryTime)

Update an existing entry or create a new one. Please note that entries starting with “qdb” are reserved.

Parameters:
  • alias – a key to uniquely identify the entry within the cluster.
  • value – the new object to associate to the key
  • expiryTime – expiry time in seconds associate to the key. The provided value is prior to the default expiry time.
Throws:
  • QuasardbException – if an error occurs (for example : lost session) or provided alias is reserved (it starts with “qdb”).
Returns:

true if entry was updated