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Name Resolution on Sun Solaris: Deadlock

Name resolution on Sun Solaris entails accessing the nscd cache. The nscd is a process that provides a cache for the most common name service requests. nscd furnishes caching for the passwd, group, and hosts databases.

The cache is not permanent. It becomes invalid as changes are made to the passwd, group, and hosts databases, or as the time‑to‑live stamp expires.

The Sun Solaris setup can create a deadlock like the one described in the previous section. Here, the interaction between CA ControlMinder and the nscd process causes the deadlock.

  1. During name resolution, CA ControlMinder accesses the nscd cache.
  2. The nscd process can decide that the cache is too old. In this case, it attempts to refresh the information by accessing the passwd, group, and hosts databases (locally or on a server).
  3. The request to access these databases is intercepted by the kernel extension. Since a CA ControlMinder process is not making the request, it is placed on a queue awaiting seosd decision. But no such decision is possible because seosd is still engaged in the previous request. The first request generates the second, and creates a deadlock.