* Improve log info in SpiLoader, improve comment and test case
* Use error level in catch block, init ArrayList with capacity and improve add item to list

* Note that this is only a temporary solution.

* Make slots loaded by SPI, mark all slots with @SpiOrder from -10000 to -1000, improve comment
* Reserve gateway and param slot chain builder (just extends DefaultSlotChainBuilder) and mark them as @Deprecated

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Polish placeholders in logging content to "{}"

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Move the legacy JUL methods from LogBase to BaseJulLogger.
* Add a JavaLoggingAdapter as the general JUL adapter for the Logger SPI, which makes it convenient to use (as the default logger).
* Add LoggerSpiProvider to resolve Logger SPI.
* Polish the logback demo.

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* There are two types of logger for command center and common modules specified by  annotation of `LogTarget`
* Add implementing examples in `sentinel-demo/sentinel-demo-log-logback`
* All implementations should support placeholder '{}'

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- to avoid the dependency chain: Constants -> SentinelConfig

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

* Add detailsOnCondition method in Metric interface to filter MetricNode within the time condition.
* Add rawMetricsInMin method in Node interface, which will retrieve and generate metric items from the min-level sliding window on condition.
* Add test cases for detailsOnCondition.

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- The BBR period for maxCpuUsage strategy is deprecated. Now Sentinel will just check the CPU usage value, which could avert surge of CPU usage quickly
- Improve SystemRuleManager and SystemStatusListener
- Add some test cases

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- Support customized log and configuration properties directory

* Add a ConsoleHandler to support logging into stdout and stderr.
* Add a `csp.sentinel.log.output.type` property to configure for output type of record logs (only a temporary design)
* Add millisecond to the format of CspFormatter

- improvement of #789

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

- Add two attributes in DegradeRule: rtSlowRequestAmount and minRequestAmount

* also some code cleanup

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

Signed-off-by: Carpenter Lee <hooleeucas@163.com>

Signed-off-by: Eric Zhao <sczyh16@gmail.com>