The Sync DIMMCHECK bursts complex pattern tests, into and from the tested module, at a true 133MHz synchronous rate. The automatic test provides the tested module's size, voltage, frequency, and type. The 133Mhz test engine verifies that the tested module can accept the various mode commands, including CAS latency of 1, 2, and 3, sequential, or interleave type bursts at different lengths, and the single write mode. It further verifies interleaved bank operation.
The LDAP users sync job (\auth_ldap\task\sync_task) scheduled task (new in Moodle 3.0; previously there was a CLI script, see MDL-51824 for more info) is responsible for creating and updating user information, and suspending and deleting LDAP accounts.
Sync Checker 3.3
Download: https://ssurll.com/2vFyaW
For most use cases of TSC, vsyscalls for gettimeofday() and clock_gettime() could reduce major performance overheads,because it avoids to user/kernel context switch and tries to use rdtsc instructions to get the TSC register value directly.Especially, the system calls provide better porting and error handling capabilities. For example, on some platformsan undetectable TSC sync problem found among multiple CPUs, thegettimeofday() and clock_gettime() vsyscalls try to work around the problem.
CPU feature bits can only indicate the TSC stability in a UP system. For a SMP system, there are no explicit ways could beused to ensure TSC reliability. The TSC sync test is the only way to test SMP TSC reliability.However, some virtualization solution does provide good TSC sync mechanism. In order to handle some falsepositive test results, VMware create a new syntheticTSC_RELIABLE feature bitin Linux kernel to bypass TSC sync testing. This flag is also used by other kernel components to bypass TSC synctesting. Below command could be used to check this new synthetic CPU feature,
On a UP system, CPU TSC sync behavior among multiple cores is determined by CPU TSC capability. Whereas on a SMP system,the TSC sync problem cross multiple CPU sockets could be a big problem. There are 3 type of SMP systems,
In Linux kernel CPU hotplug code path, it will check tsc sync and may disable tsc clocksource by calling mark_tsc_unstable.Linux kernel used to have TSC sync algorithm by using write_tsc call. But recent Linux code already removed the implementationdue to the sync code because there is no reliable software mechanism to make sure TSC values are exactly same by issuing multipleinstructions to multiple CPUs at exactly same time.
TSC sync functionality was highly depends on board manufacturer design. For example, clock source reliability issues.I used to encountered a hardware errata caused by unreliable clock source. Due to the errata, Linux kernel TSC synctest code(check_tsc_sync_source in tsc_sync.c)reported error messages and disabled TSC as clock source.
User application who relies on TSC sync may do above two steps check to confirm whether TSC is reliable or not. However,per the root causes of TSC problems, kernel may not able to test out all of unreliable cases. For example, it is stillpossible that TSC clock had the problem during runtime. In this case, Linux may switch clock source from tsc to otherson the fly.
Comparing with physical problems, the virtualization introduced more challenges regarding to TSC sync.For example, VM live migration may cause TSC sync problems if source and target hosts are different from hardware and software levels,
ESX 4.x and 3.x does not make TSC sync between vCPUs. But since ESX 5.x, the hypervisor always maintain the TSC got synced between vCPUs. VMware uses the hybrid algorithm to make sure TSC got synced even if underlaying hardware does not support TSC sync. For hardware with good TSC sync support, the rdtsc emulation could get good performance. But when hardware could not give TSC sync support, TSC emulation would be slower.
For this reason, in Linux guest, VMware creates a new synthetic TSC_RELIABLE feature bit to bypass Linux TSC sync testing. Linux [VMware cpu detect code] gives the good comments about TSC sync testing issues,
Hyper-V does not provide TSC emulation. For this reason, TSC on hyper-V is not reliable. But the problem is, hyper-V Linux CPU driver never reported the problem, that means the TSC clock source is still could be used if it happed to pass Linux kernel TSC sync test. Just 20 Days ago, a Linux kernel 4.3-rc1 patch had disabled the TSC clock source on Hyper-V Linux guest.
VMware and Xen seems provide best solution for TSC sync. The KVM PV emulation never addresses user space rdtscuse case problems. And hyper-V has no TSC sync solution. All these TSC sync solutions just provide the way that let Linuxkernel TSC clocksource continuously work. The tiny TSC skew may still be observed in VM although TSC sync is supported bysome hypervisors. Thus application may still have a wrong TSC duration for time measurement.
We did lots of code optimizations with the latest version (initially released in November 2020). This code optimization makes it easier to add things to the main report output and the HTML report and helps keep them in sync. If you were running older versions of Health Checker, you (hopefully) noticed a large difference in the formatting output to help make the report look more organized and cleaner.
Multibyte CJK decoders now resynchronize faster. They only ignore the firstbyte of an invalid byte sequence. For example, b'\xff\n'.decode('gb2312','replace') now returns a \n after the replacement character.
ExitStack now provides a solid foundation forprogrammatic manipulation of context managers and similar cleanupfunctionality. Unlike the previous contextlib.nested API (which wasdeprecated and removed), the new API is designed to work correctlyregardless of whether context managers acquire their resources intheir __init__ method (for example, file objects) or in their__enter__ method (for example, synchronisation objects from thethreading module).
New methods multiprocessing.pool.Pool.starmap() andstarmap_async() provideitertools.starmap() equivalents to the existingmultiprocessing.pool.Pool.map() andmap_async() functions. (Contributed by HynekSchlawack in bpo-12708.)
The default validation checks for synchronization of the NTP server with all nodes in the network. It is always important to have your devices in time synchronization to ensure configuration and management events can be tracked and correlations can be made between events.
Sometimes it is useful to run validations on more than one protocol simultaneously. This gives a view into any potential relationship between the protocols or services status. For example, you might want to compare NTP with Agent validations if NetQ Agents are losing connectivity or the data appears to be collected at the wrong time. It would help determine if loss of time synchronization is causing the issue.
Test execution is managed with test runs. A test run is a snapshot of your project that includes all the tests or just a subset of them. A test run creates a kind of branch of the project where current definitions of tests are stored. It means that you can continue working on your scenarios and modify them without impacting the test run and the execution. Of course your can synchronize your test run at any time with the new definitions of scenarios.
Asynchronous code is common in modern Javascript applications. Testing it is mostly the same as testing synchronous code, except for one key difference: Jasmine needs to know when the asynchronous work is finished.
Usually, the most convenient way to write async tests is to use async/await. async functions implicitly return a promise. Jasmine will wait until the returned promise is either resolved or rejected before moving on to the next thing in the queue. Rejected promises will cause a spec failure, or a suite-level failure in the case of beforeAll or afterAll. 2ff7e9595c
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