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pads:gaia-apis [2010/11/10 13:36] – gdangelopads:gaia-apis [2017/12/20 07:48] (current) – gdangelo
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 //none// //none//
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----- 
- 
  
 **Return value:** **Return value:**
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 **Description**: **Description**:
  
-Returns the length of the time-step used in the simulation. This parameter is initialized using the **GLOBAL_LA** parameters as defined in the file "**channels.txt**". For example, GLOBAL_LA=1 defines a global lookahead (timestep) of 1 time-unit, and GLOBAL_LA=0.01 is to define timesteps with a length of 1/100 of time-unit.+Returns the length of the timestep used in the simulation. This parameter is initialized using the **GLOBAL_LA** parameters as defined in the file "**channels.txt**". For example, GLOBAL_LA=1 defines a global lookahead (timestep) of 1 time-unit, and GLOBAL_LA=0.01 is to define timesteps with a length of 1/100 of time-unit.
  
 **Notes**: **Notes**:
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 **Return value:** **Return value:**
  
-The time-step length (double).+The timestep length (double).
  
 ---- ----
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 The default value of E3_EVENT_COUNTDOWN is 30 events. The default value of E3_EVENT_COUNTDOWN is 30 events.
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 **Return value:** **Return value:**
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 ^ Migration heuristic      ^  SetHistory() semantic       ^ ^ Migration heuristic      ^  SetHistory() semantic       ^
 | MIGR_OFF    |  //none//     | | MIGR_OFF    |  //none//     |
-| MIGR_ON / MIGR_E1   |   Threshold: number of times-steps (since the last reset)   |+| MIGR_ON / MIGR_E1   |   Threshold: number of timesteps (since the last reset)   |
 | MIGR_E2  |  Threshold: number of UNICAST events generated (since the last reset)  | | MIGR_E2  |  Threshold: number of UNICAST events generated (since the last reset)  |
  
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 **Description**: **Description**:
  
-All the implemented migration heuristics are based on the evaluation of the outbound UNICAST traffic generated by each Simulated Entity. The migration factor is a tuning parameters of the heuristics: a low value would increase the number of migrations, conversely a higher value would reduce the number of migrations (default value = 3). +All the implemented migration heuristics are based on the evaluation of the outbound UNICAST traffic generated by each Simulated Entity. The migration factor is a tuning parameters of the heuristics: a low value would increase the number of migrations, conversely a higher value would reduce the number of migrations (default value = 3).
  
 **Notes**: **Notes**:
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 **Description**: **Description**:
  
-The migration heuristic 1 (MIGR_ON / MIGR_E1) uses a sliding window mechanism to evaluate the communication pattern of each SE (HISTORY_SLOTS, default value = 4). The number of slots composing the sliding windows can be defined at the simulation bootstrap using this API.+The migration heuristic 1 (MIGR_ON / MIGR_E1) uses a sliding window mechanism to evaluate the communication pattern of each SE (HISTORY_SLOTS, default value = 4). The number of slots composing the sliding window can be defined at the simulation bootstrap using this API.
  
 **Notes**: **Notes**:
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 **Description**: **Description**:
  
-The migration heuristics 2 and 3 (MIGR_E2 / MIGR_E3) are based on the a sliding-windows with the last E2_EVENT_HISTORY_SIZE messages sent by the SE (default value 100). The number of events composing the sliding windows can be defined at the simulation bootstrap using this API.+The migration heuristics 2 and 3 (MIGR_E2 / MIGR_E3) are based on the a sliding window with the last E2_EVENT_HISTORY_SIZE messages sent by the SE (default value 100). The number of events composing the sliding window can be defined at the simulation bootstrap using this API.
  
 **Notes**: **Notes**:
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 **Description**: **Description**:
  
-All the implemented migration heuristics are based on the evaluation of the outbound UNICAST traffic generated by each SE (also called events). +All the implemented migration heuristics are based on the evaluation of the outbound UNICAST traffic generated by each SE (also called events).
  
 ^ Migration heuristic      ^  Description       ^  Pros  ^  Cons  ^ ^ Migration heuristic      ^  Description       ^  Pros  ^  Cons  ^
 | MIGR_OFF    |  //none//     |  none  |  none  | | MIGR_OFF    |  //none//     |  none  |  none  |
-| MIGR_ON / MIGR_E1   |  The heuristic is evaluated each time-step. It is based on the last E1_HISTORY_SLOTS timesteps of the simulation. It is implemented a sliding window approach that at each step throws away the oldest events and inserts the more recent ones  |  Very high LCR  \\  Well-suited for communication intensive models  |  In some cases, relevant overhead  |  +| MIGR_ON / MIGR_E1   |  The heuristic is evaluated each timestep. It is based on the last E1_HISTORY_SLOTS timesteps of the simulation. It is implemented a sliding window approach that at each step throws away the oldest events and inserts the more recent ones  |  Very high LCR  \\  Well-suited for communication intensive models  |  In some cases, relevant overhead  |  
-| MIGR_E2  |  The heuristic is evaluated each time-step. It is based on the a sliding-windows with the last E2_EVENT_HISTORY_SIZE messages sent by the SE  |  Well suited for simulatons in which the communication pattern of entities changes frequently   |  In some cases, relevant overhead  | +| MIGR_E2  |  The heuristic is evaluated each timestep. It is based on the a sliding window with the last E2_EVENT_HISTORY_SIZE messages sent by the SE  |  Well suited for simulations in which the communication pattern of entities changes frequently   |  In some cases, relevant overhead  | 
-| MIGR_E3  |  The heuristic is evaluated only if the SE has sent at least E3_EVENT_COUNTDOWN events after the last evaluation. The rest of the mechanism is the same as MIGR_E2  |  Well suited for simulatons with a very high number of SEs and in which the communication pattern of entities changes frequently   |  In some cases slow convergence and slightly lower LCR  |+| MIGR_E3  |  The heuristic is evaluated only if the SE has sent at least E3_EVENT_COUNTDOWN events after the last evaluation. The rest of the mechanism is the same as MIGR_E2  |  Well suited for simulations with a very high number of SEs and in which the communication pattern of entities changes frequently   |  In some cases slow convergence and slightly lower LCR  |
  
 \\ \\
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   * GAIA_SetMT(): for an introduction to the Migration Threshold, that is a mechanism that reduces the migration rate of SEs;   * GAIA_SetMT(): for an introduction to the Migration Threshold, that is a mechanism that reduces the migration rate of SEs;
   * GAIA_SetMF(): for an introduction to the Migration Factor, that is the parameter that is used to evaluate if and where activate the migration mechanism for a SE;   * GAIA_SetMF(): for an introduction to the Migration Factor, that is the parameter that is used to evaluate if and where activate the migration mechanism for a SE;
 +  * E1_HISTORY_SLOTS, default value = 4. It can be modified in the simulation setup using the GAIA_SetHistorySlots() API.
   * E2_EVENT_HISTORY_SIZE, default value = 100. It is how many events (FIFO order) are considered by migration heuristics 2 and 3. This value can be changed using the GAIA_SetEventHistorySize() API.   * E2_EVENT_HISTORY_SIZE, default value = 100. It is how many events (FIFO order) are considered by migration heuristics 2 and 3. This value can be changed using the GAIA_SetEventHistorySize() API.
   * E3_EVENT_COUNTDOWN, default value = 30. It is the interval of events before a new evaluation of the heuristic. This value can be changed using the GAIA_SetCountDown() API.   * E3_EVENT_COUNTDOWN, default value = 30. It is the interval of events before a new evaluation of the heuristic. This value can be changed using the GAIA_SetCountDown() API.
-  * HISTORY_SLOTS, default value = 4. It can be modified in the simulation setup using the GAIA_SetHistorySlots() API. 
  
 **Return value:** **Return value:**
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 **Notes**: **Notes**:
  
-The message time-stamp has to respect the constraints given by the synchronization algorithm (time-stepped).+The message time-stamp has to respect the constraints given by the synchronization algorithm (timestepped).
  
 **Return value:** **Return value:**
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 **Notes**: **Notes**:
  
-   * The message time-stamp has to respect the constraints given by the synchronization algorithm (time-stepped).+   * The message time-stamp has to respect the constraints given by the synchronization algorithm (timestepped).
  
    * This API has the exactly the same semantic of GAIA_Send(). For performance reasons, in this case the message is contained in an array instead of a String.    * This API has the exactly the same semantic of GAIA_Send(). For performance reasons, in this case the message is contained in an array instead of a String.
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 **Notes**: **Notes**:
  
-   * The message time-stamp has to respect the constraints given by the synchronization algorithm (time-stepped).+   * The message time-stamp has to respect the constraints given by the synchronization algorithm (timestepped).
  
    * Given that the message is delivered also to the SE that is originating it, it must be carefully managed to avoid loops.    * Given that the message is delivered also to the SE that is originating it, it must be carefully managed to avoid loops.
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 **Notes**: **Notes**:
  
-   * The message time-stamp has to respect the constraints given by the synchronization algorithm (time-stepped).+   * The message time-stamp has to respect the constraints given by the synchronization algorithm (timestepped).
  
    * Given that the message is delivered also to the SE that is originating it, it must be carefully managed to avoid loops.    * Given that the message is delivered also to the SE that is originating it, it must be carefully managed to avoid loops.
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 void    GAIA_SetMF (float); void    GAIA_SetMF (float);
 void    GAIA_SetMT (unsigned int); void    GAIA_SetMT (unsigned int);
 +void GAIA_SetCountDown ( int );
 +void GAIA_SetHistorySlots (int );
 +void GAIA_SetEventHistorySize (int );
 void    GAIA_SetMigration (int); void    GAIA_SetMigration (int);
 void    GAIA_SetLoadBalancing (int); void    GAIA_SetLoadBalancing (int);
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 Please refer to the description of the Java binding to have an introduction to the provided APIs. Please refer to the description of the Java binding to have an introduction to the provided APIs.
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pads/gaia-apis.1289396206.txt.gz · Last modified: by gdangelo
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