序
本文主要研究一下 Elasticsearch 的 OsProbe
OsProbe
elasticsearch-7.0.1/server/src/main/java/org/elasticsearch/monitor/os/OsProbe.java
public class OsProbe {private static final OperatingSystemMXBean osMxBean = ManagementFactory.getOperatingSystemMXBean();
private static final Method getFreePhysicalMemorySize;
private static final Method getTotalPhysicalMemorySize;
private static final Method getFreeSwapSpaceSize;
private static final Method getTotalSwapSpaceSize;
private static final Method getSystemLoadAverage;
private static final Method getSystemCpuLoad;
static {getFreePhysicalMemorySize = getMethod("getFreePhysicalMemorySize");
getTotalPhysicalMemorySize = getMethod("getTotalPhysicalMemorySize");
getFreeSwapSpaceSize = getMethod("getFreeSwapSpaceSize");
getTotalSwapSpaceSize = getMethod("getTotalSwapSpaceSize");
getSystemLoadAverage = getMethod("getSystemLoadAverage");
getSystemCpuLoad = getMethod("getSystemCpuLoad");
}
/**
* Returns the amount of free physical memory in bytes.
*/
public long getFreePhysicalMemorySize() {if (getFreePhysicalMemorySize == null) {return -1;}
try {return (long) getFreePhysicalMemorySize.invoke(osMxBean);
} catch (Exception e) {return -1;}
}
/**
* Returns the total amount of physical memory in bytes.
*/
public long getTotalPhysicalMemorySize() {if (getTotalPhysicalMemorySize == null) {return -1;}
try {return (long) getTotalPhysicalMemorySize.invoke(osMxBean);
} catch (Exception e) {return -1;}
}
/**
* Returns the amount of free swap space in bytes.
*/
public long getFreeSwapSpaceSize() {if (getFreeSwapSpaceSize == null) {return -1;}
try {return (long) getFreeSwapSpaceSize.invoke(osMxBean);
} catch (Exception e) {return -1;}
}
/**
* Returns the total amount of swap space in bytes.
*/
public long getTotalSwapSpaceSize() {if (getTotalSwapSpaceSize == null) {return -1;}
try {return (long) getTotalSwapSpaceSize.invoke(osMxBean);
} catch (Exception e) {return -1;}
}
/**
* The system load averages as an array.
*
* On Windows, this method returns {@code null}.
*
* On Linux, this method returns the 1, 5, and 15-minute load averages.
*
* On macOS, this method should return the 1-minute load average.
*
* @return the available system load averages or {@code null}
*/
final double[] getSystemLoadAverage() {if (Constants.WINDOWS) {return null;} else if (Constants.LINUX) {
try {final String procLoadAvg = readProcLoadavg();
assert procLoadAvg.matches("(\\d+\\.\\d+\\s+){3}\\d+/\\d+\\s+\\d+");
final String[] fields = procLoadAvg.split("\\s+");
return new double[]{Double.parseDouble(fields[0]), Double.parseDouble(fields[1]), Double.parseDouble(fields[2])};
} catch (final IOException e) {if (logger.isDebugEnabled()) {logger.debug("error reading /proc/loadavg", e);
}
return null;
}
} else {
assert Constants.MAC_OS_X;
if (getSystemLoadAverage == null) {return null;}
try {final double oneMinuteLoadAverage = (double) getSystemLoadAverage.invoke(osMxBean);
return new double[]{oneMinuteLoadAverage >= 0 ? oneMinuteLoadAverage : -1, -1, -1};
} catch (IllegalAccessException | InvocationTargetException e) {if (logger.isDebugEnabled()) {logger.debug("error reading one minute load average from operating system", e);
}
return null;
}
}
}
public short getSystemCpuPercent() {return Probes.getLoadAndScaleToPercent(getSystemCpuLoad, osMxBean);
}
public OsStats osStats() {final OsStats.Cpu cpu = new OsStats.Cpu(getSystemCpuPercent(), getSystemLoadAverage());
final OsStats.Mem mem = new OsStats.Mem(getTotalPhysicalMemorySize(), getFreePhysicalMemorySize());
final OsStats.Swap swap = new OsStats.Swap(getTotalSwapSpaceSize(), getFreeSwapSpaceSize());
final OsStats.Cgroup cgroup = Constants.LINUX ? getCgroup() : null;
return new OsStats(System.currentTimeMillis(), cpu, mem, swap, cgroup);
}
/**
* Returns a given method of the OperatingSystemMXBean, or null if the method is not found or unavailable.
*/
private static Method getMethod(String methodName) {
try {return Class.forName("com.sun.management.OperatingSystemMXBean").getMethod(methodName);
} catch (Exception e) {
// not available
return null;
}
}
//......
}- OsProbe 使用 static 代码块反射获取了 getFreePhysicalMemorySize、getTotalPhysicalMemorySize、getFreeSwapSpaceSize、getTotalSwapSpaceSize、getSystemLoadAverage、getSystemCpuLoad 这几个 method；它们是从 com.sun.management.OperatingSystemMXBean 获取的；osStats 方法返回 OsStats，它由 OsStats.Cpu、OsStats.Mem、OsStats.Swap、OsStats.Cgroup 这几部分组成
OsProbe.getCgroup
elasticsearch-7.0.1/server/src/main/java/org/elasticsearch/monitor/os/OsProbe.java
public class OsProbe {
//......
/**
* Basic cgroup stats.
*
* @return basic cgroup stats, or {@code null} if an I/O exception occurred reading the cgroup stats
*/
private OsStats.Cgroup getCgroup() {
try {if (!areCgroupStatsAvailable()) {return null;} else {final Map<String, String> controllerMap = getControlGroups();
assert !controllerMap.isEmpty();
final String cpuAcctControlGroup = controllerMap.get("cpuacct");
assert cpuAcctControlGroup != null;
final long cgroupCpuAcctUsageNanos = getCgroupCpuAcctUsageNanos(cpuAcctControlGroup);
final String cpuControlGroup = controllerMap.get("cpu");
assert cpuControlGroup != null;
final long cgroupCpuAcctCpuCfsPeriodMicros = getCgroupCpuAcctCpuCfsPeriodMicros(cpuControlGroup);
final long cgroupCpuAcctCpuCfsQuotaMicros = getCgroupCpuAcctCpuCfsQuotaMicros(cpuControlGroup);
final OsStats.Cgroup.CpuStat cpuStat = getCgroupCpuAcctCpuStat(cpuControlGroup);
final String memoryControlGroup = controllerMap.get("memory");
assert memoryControlGroup != null;
final String cgroupMemoryLimitInBytes = getCgroupMemoryLimitInBytes(memoryControlGroup);
final String cgroupMemoryUsageInBytes = getCgroupMemoryUsageInBytes(memoryControlGroup);
return new OsStats.Cgroup(
cpuAcctControlGroup,
cgroupCpuAcctUsageNanos,
cpuControlGroup,
cgroupCpuAcctCpuCfsPeriodMicros,
cgroupCpuAcctCpuCfsQuotaMicros,
cpuStat,
memoryControlGroup,
cgroupMemoryLimitInBytes,
cgroupMemoryUsageInBytes);
}
} catch (final IOException e) {logger.debug("error reading control group stats", e);
return null;
}
}
@SuppressForbidden(reason = "access /proc/self/cgroup, /sys/fs/cgroup/cpu, /sys/fs/cgroup/cpuacct and /sys/fs/cgroup/memory")
boolean areCgroupStatsAvailable() {if (!Files.exists(PathUtils.get("/proc/self/cgroup"))) {return false;}
if (!Files.exists(PathUtils.get("/sys/fs/cgroup/cpu"))) {return false;}
if (!Files.exists(PathUtils.get("/sys/fs/cgroup/cpuacct"))) {return false;}
if (!Files.exists(PathUtils.get("/sys/fs/cgroup/memory"))) {return false;}
return true;
}
private Map<String, String> getControlGroups() throws IOException {final List<String> lines = readProcSelfCgroup();
final Map<String, String> controllerMap = new HashMap<>();
for (final String line : lines) {
/*
* The virtual file /proc/self/cgroup lists the control groups that the Elasticsearch process is a member of. Each line contains
* three colon-separated fields of the form hierarchy-ID:subsystem-list:cgroup-path. For cgroups version 1 hierarchies, the
* subsystem-list is a comma-separated list of subsystems. The subsystem-list can be empty if the hierarchy represents a cgroups
* version 2 hierarchy. For cgroups version 1
*/
final String[] fields = line.split(":");
assert fields.length == 3;
final String[] controllers = fields[1].split(",");
for (final String controller : controllers) {
final String controlGroupPath;
if (CONTROL_GROUPS_HIERARCHY_OVERRIDE != null) {
/*
* Docker violates the relationship between /proc/self/cgroup and the /sys/fs/cgroup hierarchy. It's possible that this
* will be fixed in future versions of Docker with cgroup namespaces, but this requires modern kernels. Thus, we provide
* an undocumented hack for overriding the control group path. Do not rely on this hack, it will be removed.
*/
controlGroupPath = CONTROL_GROUPS_HIERARCHY_OVERRIDE;
} else {controlGroupPath = fields[2];
}
final String previous = controllerMap.put(controller, controlGroupPath);
assert previous == null;
}
}
return controllerMap;
}
private long getCgroupCpuAcctUsageNanos(final String controlGroup) throws IOException {return Long.parseLong(readSysFsCgroupCpuAcctCpuAcctUsage(controlGroup));
}
@SuppressForbidden(reason = "access /sys/fs/cgroup/cpuacct")
String readSysFsCgroupCpuAcctCpuAcctUsage(final String controlGroup) throws IOException {return readSingleLine(PathUtils.get("/sys/fs/cgroup/cpuacct", controlGroup, "cpuacct.usage"));
}
private long getCgroupCpuAcctCpuCfsPeriodMicros(final String controlGroup) throws IOException {return Long.parseLong(readSysFsCgroupCpuAcctCpuCfsPeriod(controlGroup));
}
@SuppressForbidden(reason = "access /sys/fs/cgroup/cpu")
String readSysFsCgroupCpuAcctCpuCfsPeriod(final String controlGroup) throws IOException {return readSingleLine(PathUtils.get("/sys/fs/cgroup/cpu", controlGroup, "cpu.cfs_period_us"));
}
private long getCgroupCpuAcctCpuCfsQuotaMicros(final String controlGroup) throws IOException {return Long.parseLong(readSysFsCgroupCpuAcctCpuAcctCfsQuota(controlGroup));
}
@SuppressForbidden(reason = "access /sys/fs/cgroup/cpu")
String readSysFsCgroupCpuAcctCpuAcctCfsQuota(final String controlGroup) throws IOException {return readSingleLine(PathUtils.get("/sys/fs/cgroup/cpu", controlGroup, "cpu.cfs_quota_us"));
}
private OsStats.Cgroup.CpuStat getCgroupCpuAcctCpuStat(final String controlGroup) throws IOException {final List<String> lines = readSysFsCgroupCpuAcctCpuStat(controlGroup);
long numberOfPeriods = -1;
long numberOfTimesThrottled = -1;
long timeThrottledNanos = -1;
for (final String line : lines) {final String[] fields = line.split("\\s+");
switch (fields[0]) {
case "nr_periods":
numberOfPeriods = Long.parseLong(fields[1]);
break;
case "nr_throttled":
numberOfTimesThrottled = Long.parseLong(fields[1]);
break;
case "throttled_time":
timeThrottledNanos = Long.parseLong(fields[1]);
break;
}
}
assert numberOfPeriods != -1;
assert numberOfTimesThrottled != -1;
assert timeThrottledNanos != -1;
return new OsStats.Cgroup.CpuStat(numberOfPeriods, numberOfTimesThrottled, timeThrottledNanos);
}
private String getCgroupMemoryLimitInBytes(final String controlGroup) throws IOException {return readSysFsCgroupMemoryLimitInBytes(controlGroup);
}
@SuppressForbidden(reason = "access /sys/fs/cgroup/memory")
String readSysFsCgroupMemoryLimitInBytes(final String controlGroup) throws IOException {return readSingleLine(PathUtils.get("/sys/fs/cgroup/memory", controlGroup, "memory.limit_in_bytes"));
}
private String getCgroupMemoryUsageInBytes(final String controlGroup) throws IOException {return readSysFsCgroupMemoryUsageInBytes(controlGroup);
}
//......
}- OsProbe.getCgroup 方法首先通过 areCgroupStatsAvailable 方法确定是否有 cgroup 的统计信息，不存在则直接返回 null；存在则通过 getControlGroups 读取相关信息构建 OsStats.Cgroup
- areCgroupStatsAvailable 方法判断
/proc/self/cgroup、/sys/fs/cgroup/cpu、/sys/fs/cgroup/cpuacct、/sys/fs/cgroup/memory这几个文件是否存在，不存在则返回 false，都存在则返回 true - getControlGroups()方法从
/proc/self/cgroup读取信息，它包括 cpu、cpuacct、memory 三部分；其中 cpu 信息从/sys/fs/cgroup/cpu读取；cpuacct 信息从/sys/fs/cgroup/cpuacct读取；memory 信息从/sys/fs/cgroup/memory读取
cgroup 信息实例
/proc/self/cgroup
cat /proc/self/cgroup
12:pids:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
11:hugetlb:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
10:net_prio:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
9:perf_event:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
8:net_cls:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
7:freezer:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
6:devices:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
5:memory:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
4:blkio:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
3:cpuacct:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
2:cpu:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845
1:cpuset:/docker/d8942cd630dbfddeb5696bd2dc134405c11433458d2aaa1845218086a2015845/sys/fs/cgroup/cpu
/sys/fs/cgroup/cpu # ls
cgroup.clone_children cpu.rt_period_us notify_on_release
cgroup.procs cpu.rt_runtime_us tasks
cpu.cfs_period_us cpu.shares
cpu.cfs_quota_us cpu.stat
cat /sys/fs/cgroup/cpu/cpu.cfs_period_us
100000
cat /sys/fs/cgroup/cpu/cpu.cfs_quota_us
-1/sys/fs/cgroup/cpuacct
/sys/fs/cgroup/cpuacct # ls
cgroup.clone_children cpuacct.usage_percpu_sys
cgroup.procs cpuacct.usage_percpu_user
cpuacct.stat cpuacct.usage_sys
cpuacct.usage cpuacct.usage_user
cpuacct.usage_all notify_on_release
cpuacct.usage_percpu tasks
cat /sys/fs/cgroup/cpuacct/cpuacct.usage
31322196847
cat /sys/fs/cgroup/cpuacct/cpuacct.stat
user 2759
system 179/sys/fs/cgroup/memory
/sys/fs/cgroup/memory # ls
cgroup.clone_children memory.memsw.failcnt
cgroup.event_control memory.memsw.limit_in_bytes
cgroup.procs memory.memsw.max_usage_in_bytes
memory.failcnt memory.memsw.usage_in_bytes
memory.force_empty memory.move_charge_at_immigrate
memory.kmem.failcnt memory.numa_stat
memory.kmem.limit_in_bytes memory.oom_control
memory.kmem.max_usage_in_bytes memory.pressure_level
memory.kmem.slabinfo memory.soft_limit_in_bytes
memory.kmem.tcp.failcnt memory.stat
memory.kmem.tcp.limit_in_bytes memory.swappiness
memory.kmem.tcp.max_usage_in_bytes memory.usage_in_bytes
memory.kmem.tcp.usage_in_bytes memory.use_hierarchy
memory.kmem.usage_in_bytes notify_on_release
memory.limit_in_bytes tasks
memory.max_usage_in_bytes
cat /sys/fs/cgroup/memory/memory.limit_in_bytes
9223372036854771712
cat /sys/fs/cgroup/memory/memory.usage_in_bytes
198819840小结
- OsProbe 使用 static 代码块反射获取了 getFreePhysicalMemorySize、getTotalPhysicalMemorySize、getFreeSwapSpaceSize、getTotalSwapSpaceSize、getSystemLoadAverage、getSystemCpuLoad 这几个 method；它们是从 com.sun.management.OperatingSystemMXBean 获取的；osStats 方法返回 OsStats，它由 OsStats.Cpu、OsStats.Mem、OsStats.Swap、OsStats.Cgroup 这几部分组成
- OsProbe.getCgroup 方法首先通过 areCgroupStatsAvailable 方法确定是否有 cgroup 的统计信息，不存在则直接返回 null；存在则通过 getControlGroups 读取相关信息构建 OsStats.Cgroup
- areCgroupStatsAvailable 方法判断
/proc/self/cgroup、/sys/fs/cgroup/cpu、/sys/fs/cgroup/cpuacct、/sys/fs/cgroup/memory这几个文件 / 目录是否存在，不存在则返回 false，都存在则返回 true；getControlGroups()方法从/proc/self/cgroup读取信息，它包括 cpu、cpuacct、memory 三部分；其中 cpu 信息从/sys/fs/cgroup/cpu读取；cpuacct 信息从/sys/fs/cgroup/cpuacct读取；memory 信息从/sys/fs/cgroup/memory读取
doc
- OsProbe