We have a distributed lock code like this, but it seems, the second thread didn't wait till first thread finished db insert
await using var handle = await _distributedLock.TryAcquireAsync($"api-lock", TimeSpan.FromMinutes(5));
try {
if (handle != null)
{
var rtCertifcate = _apiClient.CallApi (); //external API
if (!string.IsNullOrWhiteSpace(rtCertifcate ))
{
//insert into database for rtCertifcate
return rtCertifcate
}
}
else
{
// If we can't acquire the lock, fall back to database lookup
Logger.LogWarning("....");
}
}
catch
{
}
//Code read certificate from database
2 Answer(s)
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0
The ABP distributed lock (
IAbpDistributedLock.TryAcquireAsync) is designed to prevent concurrent access to shared resources. However, if the second thread does not wait for the first to finish, it is likely becauseTryAcquireAsyncreturns immediately if the lock is already held, instead of waiting for it to be released.By default,
TryAcquireAsyncuses aTimeSpan.Zerotimeout, which means it will not wait if the lock is unavailable. To make the second thread wait, you must specify a non-zero timeout value.In your code, you are passing
TimeSpan.FromMinutes(5)as the timeout, which should make the second thread wait up to 5 minutes to acquire the lock. If the lock is not acquired within this period,handlewill benull.Ensure that:
- The lock name (
"api-lock") is exactly the same for all threads. - The distributed lock provider (e.g., Redis) is properly configured and running.
- There are no exceptions or early disposals of the lock handle that could cause the lock to be released prematurely.
- The lock name (
Example usage:
await using var handle = await _distributedLock.TryAcquireAsync("api-lock", TimeSpan.FromMinutes(5)); if (handle != null) { // Critical section: only one thread can enter here at a time // Perform your database insert or API call } else { // Could not acquire the lock within the timeout Logger.LogWarning("Could not acquire distributed lock."); }If you want the second thread to always wait until the lock is available, use a sufficiently large timeout or loop with retries.
Also, make sure you are not disposing the lock handle before your critical section is complete.
Sources:
- https://abp.io/docs/latest/framework/infrastructure/distributed-locking
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0
hi
Have you added the Redis provider? https://abp.io/docs/latest/framework/infrastructure/distributed-locking#configuring-a-provider
Can you share a demo template project to show the problem?
liming.ma@volosoft.com
Thanks
