One easy way of determining how long it takes to return a page from Seam, and/or JSF is to use a phase listener. This phase listener below logs the end of each phase of the JSF lifecycle and measures the time from the start of the RESTORE_VIEW phase (the first phase in the lifecycle and the start of the request) to the end of the RENDER_RESPONSE phase which is the last one. Logging the end of each stage of the cycle lets you see what else is going on during each phase of the cycle. 

public class LogPhaseListener implements PhaseListener {

	public long startTime;

	private static final LogProvider log = Logging
			.getLogProvider(LogPhaseListener.class);

	public void afterPhase(PhaseEvent event) {
		if (event.getPhaseId() == PhaseId.RENDER_RESPONSE) {
			long endTime = System.nanoTime();
			long diffMs = (long) ((endTime - startTime) * 0.000001);
			if (log.isDebugEnabled()) {
				log.debug("Execution Time = " + diffMs + "ms");
			}
		}
		if (log.isDebugEnabled()) {
			log.debug("Executed Phase " + event.getPhaseId());
		}
	}

	public void beforePhase(PhaseEvent event) {

		if (event.getPhaseId() == PhaseId.RESTORE_VIEW) {
			startTime = System.nanoTime();
		}
	}

	public PhaseId getPhaseId() {
		return PhaseId.ANY_PHASE;
	}

}

To use this, simply add the class to your project and insert a new phase listener in the faces-config.xml file.

  <lifecycle>
    <phase-listener>package.name.LogPhaseListener</phase-listener>
  </lifecycle>

While it may not be totally accurate, it at least gives you an idea of the scale of the duration of a request (i.e. 68ms versus 394ms). I’ve used this fairly effectively in a few projects to cut out some bottlenecks as well as comparing and contrasting different JSF frameworks.

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